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Fulgides are a representative class of photochromic organic mol­ecules which exhibit several inter­esting properties for diverse applications in fields such as data storage or high-resolution spectroscopy. The crystal structures of three furyl fulgides with different steric constraints were determined and for two of the compounds both the E and Z isomer structures were defined. The compounds are 3-[(E)-1,3-dimethyl-4,5,6,7-tetra­hydro-2-benzofuran-4-yl­idene]-4-isopropyl­idene­tetra­hydro­furan-2,5-dione, C17H18O4, (I-E), 3-[(E)-1,3-dimethyl-5,6,7,8-tetra­hydro-4H-cyclo­hepta­[c]furan-4-yl­idene]-4-iso­pro­pyl­idene­tetra­hydro­furan-2,5-dione, C18H20O4, (II-E), and the Z isomer, (II-Z), and 3-isopropyl­idene-4-[(E)-1-(5-meth­oxy-2-methyl-1-benzofuran-3-yl)ethyl­idene]tetra­hydro­furan-2,5-di­one, C19H18O5, (III-E), with two molecules in the asymmetric unit, and the Z isomer, (III-Z). The structures of the E and Z isomers show only little differences in the bond lengths and angles inside the hexa­triene unit. Because of the strained geometry there are deviations in the torsion angles. Furthermore, small differences in the distances between the bond-forming C atoms in the electro­cyclization process give no explanation for the unequal photochromic behaviour.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270110049401/eg3067sup1.cif
Contains datablocks I-E, II-E, II-Z, III-E, III-Z, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270110049401/eg3067I-Esup2.hkl
Contains datablock I-E

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270110049401/eg3067II-Esup3.hkl
Contains datablock II-E

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270110049401/eg3067II-Zsup4.hkl
Contains datablock II-Z

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270110049401/eg3067III-Esup5.hkl
Contains datablock III-E

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270110049401/eg3067III-Zsup6.hkl
Contains datablock III-Z

CCDC references: 813504; 813505; 813506; 813507; 813508

Comment top

Among photochromic compounds furyl fulgides exhibit suitable properties with a high application potential (Yokoyama, 2000). Upon wavelength-specific illumination they undergo a remarkable reversible colour change, which can be followed by UV/visible spectroscopy. The photochromic reaction occurs by a photochemical ring-closing reaction of a hexatriene system and can be reversed by irradiation with light of a different wavelength. Concomitantly there is a photochemical equilibrium between the open E and Z forms. The reaction scheme below illustrates the photochromism of a furyl fulgide with variable substituents at the hexatriene moiety. One great advantage of fulgides compared with other photochromic compounds is the high thermal stability, which is due to structural modifications at the hexatriene part. This was intensively investigated by Heller et al. in the 1980 s (Darcy et al., 1981). Furthermore, electronic variations show a great influence on the UV/visible spectroscopic characteristics of a fulgide (Yokoyama et al., 1991, 1996). Steric modifications at the hexatriene unit show strong effects on the quantum yields, which correspond with the effectiveness of the photochromic reaction. Bulky substituents reduce the EZ isomerization in favour of the EC ring closure and increase the quantum yield of the latter (Yokoyama et al., 1988; Kiji et al., 1995). Because of the single bond connection between the heterocyclic part and the anhydride moiety a rotation process is possible. This process of diastereotopomerization results in an equilibrium of the (P)-Eα and (M)-Eβ conformation. With the synthesis of a series of rotation-hindered fulgides, we improve the efficiency of the photochromic reaction. This is achieved by limiting unfavourable reactions, which compete with the ring closure from the E to the C isomer. In a comparative study we analysed three furyl fulgides with different steric constraints to their furyl backbone. Fulgides (I) and (II) contain a bridging alkyl chain between the hexatriene and the furyl moieties. Therefore the rotation around the Cb—Cc bond is unfeasible and no EαEβ diastereotopomerization occurs. For fulgide (III) the rotation should be limited to a minimal amount because of benzoannulation to the furyl part. By limiting the rotation all or at least most of the photochromic molecules are available in the correct geometric conformation for cyclization. The effects of the structural modifications were investigated by UV/visible and femtosecond time-resolved transient absorption spectroscopy (Siewertsen et al., 2011; Strübe et al., 2011).

Herein we present the molecular structures of furyl fulgides (I)–(III) in the crystalline state and the detailed analysis of the bond lengths, bond angles and selected torsion angles of the hexatriene unit of each fulgide. In addition, we analysed the distances between the two bond-forming carbon atoms Ca and Cf. The structures of compounds (I)–(III) are depicted in Fig. 1. In the crystalline state the E isomers of (I)–(III) take the helical (P)-Eα conformation. This is due to the steric repulsion of the methyl groups at Ca and Cf. For (III-E) the unit cell contains two forms [(III-Ea) and (III-Eb)] with slightly different parameters owing to packing effects. Table 1 shows selected bond lengths and angles and torsion angles for the hexatriene systems of each fulgide. As expected for all structures the bond lengths inside the hexatriene unit alternate between short and long corresponding to the alternating single and double bonds. The fulgides (I)–(III) do not differ significantly with respect to bond distances and angles. These results are in agreement with previously published structures of indolyl fulgides (Wolak et al., 2002). Furthermore, the atom distances between Ca and Cf are in the same range as for the indolyl fulgides. Hence, these values can give no explanation for the different photochromic properties. Because of the strained geometry the torsion angles for fulgide (I-E) show deviations from the other compounds. At least no trend can be observed, which correlates with the photochemical observations for the E forms. The Z isomers of (II) and (III) have almost equal properties with regard to the bond lengths and angles. Discrepancies up to 15° are observed for the torsion angles. As there is no possibility for direct ZC cyclization it is not useful to make any suggestions for the correlation between the photochemical and structural properties. In summary, the small variations in the crystallographic structures give no explanation for the different photochromic behaviour.

Related literature top

For related literature, see: Darcy et al. (1981); Kiji et al. (1995); Siewertsen et al. (2011); Strübe et al. (2011); Wolak et al. (2002); Yokoyama (2000); Yokoyama et al. (1988, 1991, 1996).

Experimental top

Fulgides (I)–(III) were synthesized following the principles of the Stobbe condensation (Strübe et al., 2011). The condensation was performed using lithium diisopropylamide in tetrahydrofuran (THF) at 195 K followed by saponification with an aqueous solution of potassium hydroxide in ethanol at 343 K. For dehydration, N,N'-dicyclohexylcarbodiimide was used. Fulgides (I-E) and (III-E) were recrystallized from diethyl ether, fulgide (II) was recrystallized from cyclohexane and the (III-Z) isomer was recrystallized from ethanol. Spectroscopic data for all compounds are available in the archived CIF,

Refinement top

H atoms were placed in geometric positions and refined as riding, with C—H = 0.95–0.98 Å and Uiso(H) = 1.2Ueq(C).

Computing details top

For all compounds, data collection: COLLECT (Bruker, 2004); cell refinement: SCALEPACK (Otwinowski & Minor, 1997); data reduction: SCALEPACK and DENZO (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL-Plus (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structures of fulgides (I)–(III). H atoms have been omitted for clarity. The unit cell of (III-E) contains two forms, viz. (III-Ea) and (III-Eb). For each structure, the displacement ellipsoids are drawn at the 50% probability level.
(I-E) 3-[(E)-1,3-dimethyl-4,5,6,7-tetrahydro-2-benzofuran-4-ylidene]-4- isopropylidenetetrahydrofuran-2,5-dione top
Crystal data top
C17H18O4F(000) = 608
Mr = 286.31Dx = 1.329 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 40527 reflections
a = 8.7142 (2) Åθ = 2.9–27.5°
b = 12.0207 (3) ŵ = 0.09 mm1
c = 13.9102 (4) ÅT = 100 K
β = 100.9737 (18)°Block, light yellow
V = 1430.46 (6) Å30.27 × 0.12 × 0.10 mm
Z = 4
Data collection top
KappaCCD
diffractometer
3278 independent reflections
Radiation source: fine-focus sealed tube2810 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.044
CCD scansθmax = 27.5°, θmin = 2.9°
Absorption correction: multi-scan
(DENZO and SCALEPACK; Otwinowski & Minor, 1997)
h = 1111
Tmin = 0.975, Tmax = 0.991k = 1515
33163 measured reflectionsl = 1818
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.037Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.099H-atom parameters constrained
S = 1.02 w = 1/[σ2(Fo2) + (0.0526P)2 + 0.3631P]
where P = (Fo2 + 2Fc2)/3
3278 reflections(Δ/σ)max < 0.001
194 parametersΔρmax = 0.26 e Å3
0 restraintsΔρmin = 0.21 e Å3
Crystal data top
C17H18O4V = 1430.46 (6) Å3
Mr = 286.31Z = 4
Monoclinic, P21/nMo Kα radiation
a = 8.7142 (2) ŵ = 0.09 mm1
b = 12.0207 (3) ÅT = 100 K
c = 13.9102 (4) Å0.27 × 0.12 × 0.10 mm
β = 100.9737 (18)°
Data collection top
KappaCCD
diffractometer
3278 independent reflections
Absorption correction: multi-scan
(DENZO and SCALEPACK; Otwinowski & Minor, 1997)
2810 reflections with I > 2σ(I)
Tmin = 0.975, Tmax = 0.991Rint = 0.044
33163 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0370 restraints
wR(F2) = 0.099H-atom parameters constrained
S = 1.02Δρmax = 0.26 e Å3
3278 reflectionsΔρmin = 0.21 e Å3
194 parameters
Special details top

Experimental. General preparation of fulgides (I)–(III): a solution of diethyl isopropylidene succinate (15 mmol) in THF [tetrahydrofuran?] (15 ml) was cooled to 195 K and LDA (7.5 ml, 15 mmol; 2 M, THF/n-heptane/ethylbenzene) was added under an argon atmosphere. After stirring for 1 h the appropriate ketone (10 mmol) dissolved in THF (30 ml) was added via a syringe. The reaction mixture was allowed to warm to room temperature overnight and stirred for an additional 24 h. The reaction progress was monitored by TLC [thin layer chromatography?]. Afterwards the reaction mixture was acidified with aqueous HCl (2 M) and the aqueous layer was extracted with ethyl acetate (3 x 50 ml). The combined organic layers were washed with saturated aqueous NaCl solution, dried over MgSO4 and the solvent was removed in vacuo. The residue was dissolved in cyclohexane/ethyl acetate (7:3), filtered over silica gel and the solvent removed in vacuo again. The residue was dissolved in ethanol (60 ml) and a saturated aqueous solution of KOH (5 ml) was added. After stirring for 20 h at 343 K the reaction mixture was poured onto ice and acidified with aqueous HCl (2 M). The aqueous layer was extracted with ethyl acetate (3 x 50 ml) and the combined organic layers were washed with saturated aqueous NaCl, dried over MgSO4 and the solvent was removed in vacuo. The dark brown residue was dissolved in dichloromethane (50 ml) and N,N'-dicyclohexylcarbodiimide (4.13 g, 20 mmol) was added. After stirring for 48 h the reaction mixture was filtered over silica gel and the solvent was removed in vacuo. The products were purified by column chromatography and recrystallized from adapted solvents.

(I-E): yield 6% (recrystallized from diethyl ether); Rf=0.34 (cyclohexane/ethyl acetate 9:1); 1H NMR (500 MHz, CDCl3, 25 °C, CDCl3=7.24 p.p.m.) δ=1.29 (s, 3H; CH3), 1.71–1.80 (m, 1H; CH2), 1.76 (s, 3H; CH3), 1.96–2.03 (m, 1H; CH2), 2.16 (s, 3H; CH3), 2.43 (s, 3H; CH3), 2.46 (m, 1H; CH2), 2.49–2.59 (m, 2H; CH2), 3.81 p.p.m. (m, 1H; CH2); 13C NMR (126 MHz, CDCl3, 25 °C, CDCl3=77.0 p.p.m.) δ=11.4, 15.8, 19.7, 22.4, 24.6, 27.1, 30.5, 114.2, 117.1, 121.6, 122.1, 144.9, 149.3, 149.5, 151.2, 163.5, 164.2 p.p.m.; MS (70 eV): m/z (%): 287 (20), 286 (100) [M+], 271 (15) [M - CH3+], 243 (40), 213 (18), 199 (23), 197 (17), 128 (17), 115 (16), 43 (96); HRMS (m/z) [M+] calcd for C17H18O4: 286.11996; found 286.12060.

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.17048 (11)0.60212 (7)0.43493 (7)0.0341 (2)
O20.12908 (9)0.59003 (7)0.58849 (6)0.0266 (2)
O30.11630 (10)0.53979 (7)0.74171 (6)0.0309 (2)
O40.21962 (9)0.06363 (6)0.50423 (5)0.02193 (18)
C10.18781 (13)0.54803 (10)0.50866 (8)0.0243 (2)
C20.25216 (12)0.43615 (9)0.53530 (8)0.0208 (2)
C30.26082 (12)0.42624 (9)0.64167 (8)0.0204 (2)
C40.16289 (12)0.51753 (9)0.66828 (8)0.0237 (2)
C50.36521 (12)0.36950 (9)0.70866 (8)0.0214 (2)
C60.48904 (13)0.29856 (10)0.67894 (8)0.0245 (2)
H6A0.45360.22110.67300.037*
H6B0.58510.30380.72850.037*
H6C0.50960.32430.61580.037*
C70.37237 (14)0.37549 (10)0.81720 (8)0.0269 (3)
H7A0.28740.42280.83080.040*
H7B0.47300.40700.84890.040*
H7C0.36130.30060.84280.040*
C80.27311 (12)0.36091 (9)0.46513 (8)0.0209 (2)
C90.30105 (14)0.39744 (10)0.36569 (8)0.0264 (3)
H9A0.31550.47910.36480.032*
H9B0.20980.37770.31450.032*
C100.44906 (14)0.33828 (11)0.34531 (9)0.0287 (3)
H10A0.47730.36990.28530.034*
H10B0.53700.35260.40040.034*
C110.42584 (13)0.21292 (11)0.33238 (8)0.0269 (3)
H11A0.36520.19680.26620.032*
H11B0.52870.17570.33910.032*
C120.33982 (12)0.16915 (10)0.40873 (8)0.0218 (2)
C130.27329 (12)0.24068 (9)0.47418 (7)0.0203 (2)
C140.19929 (12)0.17166 (9)0.52943 (8)0.0206 (2)
C150.30638 (12)0.06369 (10)0.43030 (8)0.0223 (2)
C160.09632 (13)0.18821 (9)0.60192 (8)0.0240 (2)
H16A0.02460.12500.59920.036*
H16B0.03600.25690.58660.036*
H16C0.16040.19360.66780.036*
C170.34399 (14)0.04732 (10)0.39439 (9)0.0276 (3)
H17A0.41300.03850.34690.041*
H17B0.24730.08440.36280.041*
H17C0.39650.09240.44970.041*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0386 (5)0.0286 (5)0.0335 (5)0.0061 (4)0.0033 (4)0.0097 (4)
O20.0250 (4)0.0217 (4)0.0325 (5)0.0043 (3)0.0041 (3)0.0006 (3)
O30.0303 (4)0.0319 (5)0.0319 (5)0.0039 (3)0.0094 (4)0.0083 (4)
O40.0244 (4)0.0215 (4)0.0202 (4)0.0018 (3)0.0052 (3)0.0017 (3)
C10.0207 (5)0.0227 (6)0.0281 (6)0.0005 (4)0.0012 (4)0.0013 (4)
C20.0184 (5)0.0215 (5)0.0219 (5)0.0003 (4)0.0024 (4)0.0012 (4)
C30.0193 (5)0.0206 (5)0.0216 (5)0.0013 (4)0.0047 (4)0.0031 (4)
C40.0197 (5)0.0222 (5)0.0280 (6)0.0012 (4)0.0018 (4)0.0035 (4)
C50.0223 (5)0.0193 (5)0.0225 (5)0.0030 (4)0.0042 (4)0.0024 (4)
C60.0227 (5)0.0248 (6)0.0248 (5)0.0023 (4)0.0015 (4)0.0001 (4)
C70.0312 (6)0.0282 (6)0.0203 (5)0.0002 (5)0.0023 (4)0.0016 (4)
C80.0178 (5)0.0244 (6)0.0199 (5)0.0002 (4)0.0021 (4)0.0014 (4)
C90.0313 (6)0.0276 (6)0.0202 (5)0.0026 (5)0.0049 (4)0.0023 (4)
C100.0283 (6)0.0369 (7)0.0225 (6)0.0072 (5)0.0088 (4)0.0010 (5)
C110.0235 (5)0.0357 (7)0.0228 (5)0.0007 (5)0.0073 (4)0.0031 (5)
C120.0185 (5)0.0279 (6)0.0187 (5)0.0013 (4)0.0024 (4)0.0024 (4)
C130.0189 (5)0.0241 (6)0.0174 (5)0.0004 (4)0.0021 (4)0.0018 (4)
C140.0216 (5)0.0204 (5)0.0190 (5)0.0021 (4)0.0018 (4)0.0016 (4)
C150.0194 (5)0.0289 (6)0.0183 (5)0.0021 (4)0.0025 (4)0.0037 (4)
C160.0266 (5)0.0228 (6)0.0245 (5)0.0002 (4)0.0096 (4)0.0002 (4)
C170.0286 (6)0.0283 (6)0.0255 (6)0.0028 (5)0.0041 (5)0.0072 (5)
Geometric parameters (Å, º) top
O1—C11.1993 (15)C8—C91.5145 (15)
O2—C41.3977 (14)C9—C101.5456 (17)
O2—C11.4023 (14)C9—H9A0.9900
O3—C41.1990 (14)C9—H9B0.9900
O4—C141.3654 (13)C10—C111.5265 (18)
O4—C151.3875 (13)C10—H10A0.9900
C1—C21.4769 (15)C10—H10B0.9900
C2—C81.3682 (15)C11—C121.5066 (15)
C2—C31.4721 (15)C11—H11A0.9900
C3—C51.3559 (15)C11—H11B0.9900
C3—C41.4797 (15)C12—C151.3473 (17)
C5—C61.4940 (15)C12—C131.4510 (15)
C5—C71.5008 (15)C13—C141.3725 (15)
C5—C143.5482 (15)C14—C161.4852 (15)
C6—H6A0.9800C15—C171.4832 (16)
C6—H6B0.9800C16—H16A0.9800
C6—H6C0.9800C16—H16B0.9800
C7—H7A0.9800C16—H16C0.9800
C7—H7B0.9800C17—H17A0.9800
C7—H7C0.9800C17—H17B0.9800
C8—C131.4507 (16)C17—H17C0.9800
C4—O2—C1110.54 (9)H9A—C9—H9B108.4
C14—O4—C15107.79 (8)C11—C10—C9112.29 (9)
O1—C1—O2118.46 (10)C11—C10—H10A109.1
O1—C1—C2133.49 (11)C9—C10—H10A109.1
O2—C1—C2107.91 (9)C11—C10—H10B109.1
C8—C2—C3132.48 (10)C9—C10—H10B109.1
C8—C2—C1121.26 (10)H10A—C10—H10B107.9
C3—C2—C1105.68 (9)C12—C11—C10109.53 (10)
C5—C3—C2129.11 (10)C12—C11—H11A109.8
C5—C3—C4123.00 (10)C10—C11—H11A109.8
C2—C3—C4105.65 (9)C12—C11—H11B109.8
O3—C4—O2118.88 (10)C10—C11—H11B109.8
O3—C4—C3133.12 (11)H11A—C11—H11B108.2
O2—C4—C3107.95 (9)C15—C12—C13106.77 (10)
C3—C5—C6121.49 (10)C15—C12—C11130.04 (10)
C3—C5—C7124.14 (10)C13—C12—C11123.17 (10)
C6—C5—C7114.32 (10)C14—C13—C8131.14 (10)
C5—C6—H6A109.5C14—C13—C12106.24 (10)
C5—C6—H6B109.5C8—C13—C12122.00 (10)
H6A—C6—H6B109.5O4—C14—C13109.47 (9)
C5—C6—H6C109.5O4—C14—C16115.24 (9)
H6A—C6—H6C109.5C13—C14—C16135.09 (10)
H6B—C6—H6C109.5C12—C15—O4109.70 (9)
C5—C7—H7A109.5C12—C15—C17134.46 (10)
C5—C7—H7B109.5O4—C15—C17115.83 (10)
H7A—C7—H7B109.5C14—C16—H16A109.5
C5—C7—H7C109.5C14—C16—H16B109.5
H7A—C7—H7C109.5H16A—C16—H16B109.5
H7B—C7—H7C109.5C14—C16—H16C109.5
C2—C8—C13126.50 (10)H16A—C16—H16C109.5
C2—C8—C9121.76 (10)H16B—C16—H16C109.5
C13—C8—C9111.74 (10)C15—C17—H17A109.5
C8—C9—C10108.60 (9)C15—C17—H17B109.5
C8—C9—H9A110.0H17A—C17—H17B109.5
C10—C9—H9A110.0C15—C17—H17C109.5
C8—C9—H9B110.0H17A—C17—H17C109.5
C10—C9—H9B110.0H17B—C17—H17C109.5
C2—C8—C13—C1428.51 (18)C2—C8—C13—C12161.82 (10)
C3—C2—C8—C1316.47 (19)C1—C2—C3—C5147.93 (11)
C8—C2—C3—C541.06 (19)
(II-E) 3-[(E)-1,3-dimethyl-5,6,7,8-tetrahydro-4H- cyclohepta[c]furan-4-ylidene]-4-isopropylidenetetrahydrofuran-2,5-dione top
Crystal data top
C18H20O4F(000) = 640
Mr = 300.34Dx = 1.341 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 17726 reflections
a = 9.1881 (2) Åθ = 2.9–27.5°
b = 12.0022 (3) ŵ = 0.09 mm1
c = 13.7215 (3) ÅT = 100 K
β = 100.4329 (13)°Fragment, yellow
V = 1488.16 (6) Å30.30 × 0.30 × 0.20 mm
Z = 4
Data collection top
KappaCCD
diffractometer
3402 independent reflections
Radiation source: fine-focus sealed tube2822 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.037
CCD scansθmax = 27.5°, θmin = 2.9°
Absorption correction: multi-scan
(DENZO and SCALEPACK; Otwinowski & Minor, 1997)
h = 1111
Tmin = 0.972, Tmax = 0.982k = 1515
28601 measured reflectionsl = 1717
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.035Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.091H-atom parameters constrained
S = 1.06 w = 1/[σ2(Fo2) + (0.0454P)2 + 0.3366P]
where P = (Fo2 + 2Fc2)/3
3402 reflections(Δ/σ)max < 0.001
203 parametersΔρmax = 0.24 e Å3
0 restraintsΔρmin = 0.22 e Å3
Crystal data top
C18H20O4V = 1488.16 (6) Å3
Mr = 300.34Z = 4
Monoclinic, P21/nMo Kα radiation
a = 9.1881 (2) ŵ = 0.09 mm1
b = 12.0022 (3) ÅT = 100 K
c = 13.7215 (3) Å0.30 × 0.30 × 0.20 mm
β = 100.4329 (13)°
Data collection top
KappaCCD
diffractometer
3402 independent reflections
Absorption correction: multi-scan
(DENZO and SCALEPACK; Otwinowski & Minor, 1997)
2822 reflections with I > 2σ(I)
Tmin = 0.972, Tmax = 0.982Rint = 0.037
28601 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0350 restraints
wR(F2) = 0.091H-atom parameters constrained
S = 1.06Δρmax = 0.24 e Å3
3402 reflectionsΔρmin = 0.22 e Å3
203 parameters
Special details top

Experimental. General preparation of fulgides (I)–(III): a solution of diethyl isopropylidene succinate (15 mmol) in THF [tetrahydrofuran?] (15 ml) was cooled to 195 K and LDA (7.5 ml, 15 mmol; 2 M, THF/n-heptane/ethylbenzene) was added under an argon atmosphere. After stirring for 1 h the appropriate ketone (10 mmol) dissolved in THF (30 ml) was added via a syringe. The reaction mixture was allowed to warm to room temperature overnight and stirred for an additional 24 h. The reaction progress was monitored by TLC [thin layer chromatography?]. Afterwards the reaction mixture was acidified with aqueous HCl (2 M) and the aqueous layer was extracted with ethyl acetate (3 x 50 ml). The combined organic layers were washed with saturated aqueous NaCl solution, dried over MgSO4 and the solvent was removed in vacuo. The residue was dissolved in cyclohexane/ethyl acetate (7:3), filtered over silica gel and the solvent removed in vacuo again. The residue was dissolved in ethanol (60 ml) and a saturated aqueous solution of KOH (5 ml) was added. After stirring for 20 h at 343 K the reaction mixture was poured onto ice and acidified with aqueous HCl (2 M). The aqueous layer was extracted with ethyl acetate (3 x 50 ml) and the combined organic layers were washed with saturated aqueous NaCl, dried over MgSO4 and the solvent was removed in vacuo. The dark brown residue was dissolved in dichloromethane (50 ml) and N,N'-dicyclohexylcarbodiimide (4.13 g, 20 mmol) was added. After stirring for 48 h the reaction mixture was filtered over silica gel and the solvent was removed in vacuo. The products were purified by column chromatography and recrystallized from adapted solvents.

(II-E): yield 12% (recrystallized from cyclohexane); Rf=0.75 (cyclohexane/ethyl acetate 7:3); 1H NMR (500 MHz, CDCl3, 25 °C, CDCl3=7.24 p.p.m.) δ=1.33 (s, 3H; CH3), 1.61–1.65 (m, 2H; CH2), 1.82 (s, 3H; CH3), 1.84 (m, 1H; CH2), 2.11 (m, 2H; CH2), 2.15 (s, 3H; CH3), 2.27 (m, 1H; CH2), 2.32 (s, 3H; CH3), 2.54–2.59 (m, 1H; CH2), 4.05–4.09 p.p.m. (m, 1H; CH2); 13C NMR (126 MHz, CDCl3, 25 °C, CDCl3=77.0 p.p.m.) δ=11.2, 13.5, 22.6, 24.2, 26.9, 27.8, 29.1, 33.8, 117.5, 118.4, 121.1, 125.2, 145.0, 145.8, 152.7, 153.4, 163.3, 163.6 p.p.m.; MS (70 eV): m/z (%): 301 (20), 300 (100) [M+], 285 (14) [M - CH3+], 257 (30), 243 (14), 241 (21), 213 (18), 128 (13), 115 (13), 43 (84); HRMS (m/z) [M+] calcd for C18H20O4: 300.13616; found 300.13550.

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.12492 (9)0.08179 (6)0.59955 (6)0.02215 (19)
O20.16590 (10)0.10488 (7)0.44519 (6)0.0293 (2)
O30.12198 (9)0.02503 (7)0.75441 (6)0.0262 (2)
O40.20776 (8)0.44140 (6)0.50505 (5)0.01798 (18)
C10.17786 (12)0.04453 (9)0.51581 (8)0.0202 (2)
C20.23475 (11)0.07004 (9)0.53585 (8)0.0168 (2)
C30.25159 (12)0.08321 (9)0.64427 (8)0.0172 (2)
C40.16139 (12)0.00611 (9)0.67754 (8)0.0197 (2)
C50.24428 (11)0.14295 (9)0.46082 (8)0.0166 (2)
C60.25284 (11)0.26413 (9)0.47010 (7)0.0164 (2)
C70.18172 (12)0.33271 (9)0.52588 (8)0.0170 (2)
C80.29788 (12)0.44209 (9)0.43448 (8)0.0181 (2)
C90.32620 (12)0.33669 (9)0.40900 (8)0.0179 (2)
C100.42607 (13)0.30229 (10)0.33801 (9)0.0225 (2)
H10A0.50010.36160.33540.027*
H10B0.36620.29410.27070.027*
C110.50655 (13)0.19235 (10)0.36850 (9)0.0235 (3)
H11A0.59380.18700.33570.028*
H11B0.54290.19330.44100.028*
C120.40986 (13)0.08885 (10)0.34218 (9)0.0240 (3)
H12A0.45500.02580.38340.029*
H12B0.40950.06940.27200.029*
C130.24857 (12)0.10289 (10)0.35710 (8)0.0206 (2)
H13A0.19720.15730.30850.025*
H13B0.19610.03070.34550.025*
C140.35545 (12)0.14023 (9)0.70774 (8)0.0180 (2)
C150.37122 (14)0.13546 (10)0.81852 (8)0.0236 (3)
H15A0.28980.09170.83620.035*
H15B0.36830.21120.84480.035*
H15C0.46580.10040.84680.035*
C160.47023 (13)0.20922 (9)0.67179 (8)0.0213 (2)
H16A0.47690.18720.60400.032*
H16B0.56620.19760.71510.032*
H16C0.44290.28810.67280.032*
C170.07966 (13)0.31605 (9)0.59678 (9)0.0219 (2)
H17A0.13630.31570.66460.033*
H17B0.02810.24470.58310.033*
H17C0.00710.37670.58960.033*
C180.34789 (13)0.55382 (9)0.40774 (9)0.0226 (2)
H18A0.41200.54580.35830.034*
H18B0.40310.59010.46710.034*
H18C0.26160.59930.38020.034*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0211 (4)0.0166 (4)0.0287 (4)0.0034 (3)0.0043 (3)0.0011 (3)
O20.0379 (5)0.0200 (4)0.0285 (5)0.0045 (4)0.0020 (4)0.0060 (4)
O30.0266 (4)0.0250 (4)0.0290 (5)0.0021 (3)0.0104 (4)0.0055 (4)
O40.0203 (4)0.0150 (4)0.0191 (4)0.0011 (3)0.0048 (3)0.0011 (3)
C10.0171 (5)0.0175 (5)0.0250 (6)0.0002 (4)0.0010 (4)0.0006 (4)
C20.0138 (5)0.0160 (5)0.0201 (5)0.0000 (4)0.0017 (4)0.0022 (4)
C30.0167 (5)0.0153 (5)0.0200 (5)0.0021 (4)0.0049 (4)0.0022 (4)
C40.0165 (5)0.0177 (5)0.0248 (6)0.0019 (4)0.0030 (4)0.0026 (4)
C50.0125 (5)0.0179 (5)0.0192 (5)0.0010 (4)0.0019 (4)0.0013 (4)
C60.0159 (5)0.0179 (5)0.0149 (5)0.0001 (4)0.0019 (4)0.0009 (4)
C70.0176 (5)0.0152 (5)0.0176 (5)0.0018 (4)0.0015 (4)0.0011 (4)
C80.0165 (5)0.0208 (5)0.0167 (5)0.0009 (4)0.0020 (4)0.0029 (4)
C90.0166 (5)0.0204 (5)0.0164 (5)0.0010 (4)0.0018 (4)0.0020 (4)
C100.0222 (6)0.0260 (6)0.0207 (6)0.0013 (5)0.0077 (4)0.0029 (5)
C110.0200 (6)0.0308 (6)0.0209 (6)0.0049 (5)0.0066 (4)0.0009 (5)
C120.0264 (6)0.0268 (6)0.0194 (5)0.0072 (5)0.0057 (4)0.0011 (5)
C130.0227 (6)0.0204 (5)0.0179 (5)0.0019 (4)0.0016 (4)0.0014 (4)
C140.0197 (5)0.0142 (5)0.0202 (5)0.0028 (4)0.0039 (4)0.0007 (4)
C150.0297 (6)0.0211 (6)0.0191 (5)0.0007 (5)0.0021 (5)0.0007 (4)
C160.0217 (6)0.0192 (6)0.0223 (6)0.0036 (4)0.0023 (4)0.0006 (4)
C170.0237 (6)0.0183 (5)0.0257 (6)0.0001 (4)0.0098 (5)0.0002 (4)
C180.0237 (6)0.0204 (6)0.0231 (6)0.0025 (5)0.0026 (5)0.0047 (5)
Geometric parameters (Å, º) top
O1—C41.3975 (14)C11—C121.5319 (17)
O1—C11.3997 (14)C11—H11A0.9900
O2—C11.1988 (14)C11—H11B0.9900
O3—C41.1973 (14)C12—C131.5416 (16)
O4—C71.3658 (13)C12—H12A0.9900
O4—C81.3834 (13)C12—H12B0.9900
C1—C21.4790 (15)C13—H13A0.9900
C2—C51.3661 (15)C13—H13B0.9900
C2—C31.4761 (15)C14—C161.4931 (15)
C3—C141.3552 (16)C14—C151.5017 (15)
C3—C41.4770 (15)C15—H15A0.9800
C5—C61.4609 (15)C15—H15B0.9800
C5—C131.5094 (15)C15—H15C0.9800
C6—C71.3679 (15)C16—H16A0.9800
C6—C91.4562 (15)C16—H16B0.9800
C7—C171.4820 (15)C16—H16C0.9800
C7—C143.5594 (15)C17—H17A0.9800
C8—C91.3503 (16)C17—H17B0.9800
C8—C181.4849 (15)C17—H17C0.9800
C9—C101.5117 (15)C18—H18A0.9800
C10—C111.5332 (16)C18—H18B0.9800
C10—H10A0.9900C18—H18C0.9800
C10—H10B0.9900
C4—O1—C1110.50 (8)H11A—C11—H11B107.7
C7—O4—C8107.57 (8)C11—C12—C13114.23 (9)
O2—C1—O1118.41 (10)C11—C12—H12A108.7
O2—C1—C2133.60 (11)C13—C12—H12A108.7
O1—C1—C2107.94 (9)C11—C12—H12B108.7
C5—C2—C3132.98 (10)C13—C12—H12B108.7
C5—C2—C1121.61 (10)H12A—C12—H12B107.6
C3—C2—C1104.83 (9)C5—C13—C12110.48 (9)
C14—C3—C2129.41 (10)C5—C13—H13A109.6
C14—C3—C4122.49 (10)C12—C13—H13A109.6
C2—C3—C4105.75 (9)C5—C13—H13B109.6
O3—C4—O1118.85 (10)C12—C13—H13B109.6
O3—C4—C3133.32 (11)H13A—C13—H13B108.1
O1—C4—C3107.77 (9)C3—C14—C16121.68 (10)
C2—C5—C6125.58 (10)C3—C14—C15123.98 (10)
C2—C5—C13121.52 (10)C16—C14—C15114.27 (10)
C6—C5—C13112.90 (9)C14—C15—H15A109.5
C7—C6—C9106.26 (10)C14—C15—H15B109.5
C7—C6—C5128.62 (10)H15A—C15—H15B109.5
C9—C6—C5124.64 (9)C14—C15—H15C109.5
O4—C7—C6109.76 (9)H15A—C15—H15C109.5
O4—C7—C17114.95 (9)H15B—C15—H15C109.5
C6—C7—C17135.17 (10)C14—C16—H16A109.5
C9—C8—O4110.08 (9)C14—C16—H16B109.5
C9—C8—C18134.37 (10)H16A—C16—H16B109.5
O4—C8—C18115.44 (9)C14—C16—H16C109.5
C8—C9—C6106.28 (9)H16A—C16—H16C109.5
C8—C9—C10126.21 (10)H16B—C16—H16C109.5
C6—C9—C10127.30 (10)C7—C17—H17A109.5
C9—C10—C11112.23 (9)C7—C17—H17B109.5
C9—C10—H10A109.2H17A—C17—H17B109.5
C11—C10—H10A109.2C7—C17—H17C109.5
C9—C10—H10B109.2H17A—C17—H17C109.5
C11—C10—H10B109.2H17B—C17—H17C109.5
H10A—C10—H10B107.9C8—C18—H18A109.5
C12—C11—C10113.78 (10)C8—C18—H18B109.5
C12—C11—H11A108.8H18A—C18—H18B109.5
C10—C11—H11A108.8C8—C18—H18C109.5
C12—C11—H11B108.8H18A—C18—H18C109.5
C10—C11—H11B108.8H18B—C18—H18C109.5
C2—C5—C6—C737.86 (17)C2—C5—C6—C9151.11 (11)
C3—C2—C5—C610.38 (19)C1—C2—C3—C14144.83 (11)
C5—C2—C3—C1444.14 (19)
(II-Z) 3-[(Z)-1,3-dimethyl-5,6,7,8-tetrahydro-4H-cyclohepta[c]furan-4-ylidene]-4-isopropylidenetetrahydrofuran-2,5-dione top
Crystal data top
C18H20O4F(000) = 1280
Mr = 300.34Dx = 1.319 Mg m3
Orthorhombic, PbcaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2abCell parameters from 45246 reflections
a = 8.7024 (2) Åθ = 2.9–27.5°
b = 12.8964 (4) ŵ = 0.09 mm1
c = 26.9492 (7) ÅT = 100 K
V = 3024.50 (14) Å3Fragment, yellow
Z = 80.30 × 0.30 × 0.26 mm
Data collection top
KappaCCD
diffractometer
3444 independent reflections
Radiation source: fine-focus sealed tube2657 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.063
CCD scansθmax = 27.4°, θmin = 2.9°
Absorption correction: multi-scan
(DENZO and SCALEPACK; Otwinowski & Minor, 1997)
h = 1111
Tmin = 0.973, Tmax = 0.976k = 1616
29108 measured reflectionsl = 3434
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.038Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.097H-atom parameters constrained
S = 1.03 w = 1/[σ2(Fo2) + (0.0423P)2 + 0.8467P]
where P = (Fo2 + 2Fc2)/3
3444 reflections(Δ/σ)max < 0.001
203 parametersΔρmax = 0.21 e Å3
0 restraintsΔρmin = 0.19 e Å3
Crystal data top
C18H20O4V = 3024.50 (14) Å3
Mr = 300.34Z = 8
Orthorhombic, PbcaMo Kα radiation
a = 8.7024 (2) ŵ = 0.09 mm1
b = 12.8964 (4) ÅT = 100 K
c = 26.9492 (7) Å0.30 × 0.30 × 0.26 mm
Data collection top
KappaCCD
diffractometer
3444 independent reflections
Absorption correction: multi-scan
(DENZO and SCALEPACK; Otwinowski & Minor, 1997)
2657 reflections with I > 2σ(I)
Tmin = 0.973, Tmax = 0.976Rint = 0.063
29108 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0380 restraints
wR(F2) = 0.097H-atom parameters constrained
S = 1.03Δρmax = 0.21 e Å3
3444 reflectionsΔρmin = 0.19 e Å3
203 parameters
Special details top

Experimental. General preparation of fulgides (I)–(III): a solution of diethyl isopropylidene succinate (15 mmol) in THF [tetrahydrofuran?] (15 ml) was cooled to 195 K and LDA (7.5 ml, 15 mmol; 2 M, THF/n-heptane/ethylbenzene) was added under an argon atmosphere. After stirring for 1 h the appropriate ketone (10 mmol) dissolved in THF (30 ml) was added via a syringe. The reaction mixture was allowed to warm to room temperature overnight and stirred for an additional 24 h. The reaction progress was monitored by TLC [thin layer chromatography?]. Afterwards the reaction mixture was acidified with aqueous HCl (2 M) and the aqueous layer was extracted with ethyl acetate (3 x 50 ml). The combined organic layers were washed with saturated aqueous NaCl solution, dried over MgSO4 and the solvent was removed in vacuo. The residue was dissolved in cyclohexane/ethyl acetate (7:3), filtered over silica gel and the solvent removed in vacuo again. The residue was dissolved in ethanol (60 ml) and a saturated aqueous solution of KOH (5 ml) was added. After stirring for 20 h at 343 K the reaction mixture was poured onto ice and acidified with aqueous HCl (2 M). The aqueous layer was extracted with ethyl acetate (3 x 50 ml) and the combined organic layers were washed with saturated aqueous NaCl, dried over MgSO4 and the solvent was removed in vacuo. The dark brown residue was dissolved in dichloromethane (50 ml) and N,N'-dicyclohexylcarbodiimide (4.13 g, 20 mmol) was added. After stirring for 48 h the reaction mixture was filtered over silica gel and the solvent was removed in vacuo. The products were purified by column chromatography and recrystallized from adapted solvents.

(II-Z): yield 9% (recrystallized from cyclohexane); Rf=0.65 (cyclohexane/ethyl acetate 7:3); 1H NMR (500 MHz, CDCl3, 25 °C, CDCl3=7.24 p.p.m.) δ=1.41–1.55 (m, 2H; CH2), 1.90 (m, 1H; CH2), 1.94 (s, 3H; CH3), 2.04 (m, 1H; CH2), 2.13 (s, 3H; CH3), 2.16 (s, 3H; CH3), 2.18 (m, 1H; CH2), 2.24 (m, 1H; CH2), 2.38 (s, 3H; CH3), 2.55–2.62 p.p.m. (m, 2H; CH2); 13C NMR (126 MHz, CDCl3, 25 °C, CDCl3=77.0 p.p.m.) δ=11.2, 13.3, 22.1, 25.2, 26.5, 28.4, 29.8, 37.6, 117.8, 118.2, 121.3, 121.8, 145.0, 151.2, 152.2, 153.4, 161.1, 163.8 p.p.m.; MS (70 eV): m/z (%): 301 (21), 300 (100) [M+], 285 (17) [M - CH3+], 257 (35), 255 (16), 243 (16), 241 (23), 239 (18), 229 (15), 213 (25), 211 (18), 185 (16), 128 (16), 115 (16), 43 (92); HRMS (m/z) [M+] calcd for C18H20O4: 300.13616; found 300.13330.

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.53129 (11)0.43365 (7)0.11324 (3)0.0273 (2)
O20.53720 (11)0.56871 (8)0.16557 (3)0.0314 (2)
O30.48045 (12)0.32049 (7)0.05236 (4)0.0329 (2)
O40.35706 (10)0.85114 (7)0.17899 (3)0.0254 (2)
C10.47246 (14)0.52835 (11)0.13159 (5)0.0243 (3)
C20.32999 (14)0.55136 (10)0.10408 (5)0.0220 (3)
C30.32620 (14)0.47785 (10)0.06239 (5)0.0227 (3)
C40.44516 (15)0.39940 (10)0.07322 (5)0.0255 (3)
C50.21609 (14)0.61393 (10)0.12253 (4)0.0212 (3)
C60.25087 (15)0.70148 (10)0.15504 (4)0.0216 (3)
C70.36679 (15)0.77046 (10)0.14635 (5)0.0236 (3)
C80.23199 (15)0.83183 (10)0.20975 (5)0.0244 (3)
C90.16277 (14)0.74260 (10)0.19642 (4)0.0226 (3)
C100.02622 (15)0.69378 (11)0.22104 (5)0.0258 (3)
H10A0.01570.74290.24580.031*
H10B0.06040.63100.23910.031*
C110.10143 (15)0.66369 (11)0.18522 (5)0.0254 (3)
H11A0.12710.72440.16430.030*
H11B0.19430.64530.20450.030*
C120.05940 (14)0.57284 (10)0.15162 (5)0.0241 (3)
H12A0.15560.54380.13780.029*
H12B0.01170.51830.17230.029*
C130.05009 (14)0.59670 (10)0.10810 (5)0.0228 (3)
H13A0.04550.53840.08420.027*
H13B0.01240.65940.09080.027*
C140.26593 (15)0.48959 (10)0.01639 (4)0.0244 (3)
C150.18760 (15)0.58745 (11)0.00039 (5)0.0281 (3)
H15A0.07700.57480.00300.042*
H15B0.22950.60990.03160.042*
H15C0.20500.64160.02530.042*
C160.28152 (16)0.40756 (11)0.02309 (5)0.0316 (3)
H16A0.38790.38270.02400.047*
H16B0.25420.43710.05540.047*
H16C0.21260.34960.01550.047*
C170.49192 (16)0.77903 (11)0.10941 (5)0.0308 (3)
H17A0.50620.85200.10030.046*
H17B0.46510.73890.07980.046*
H17C0.58740.75190.12370.046*
C180.20589 (16)0.91077 (11)0.24902 (5)0.0319 (3)
H18A0.11670.89080.26910.048*
H18B0.18680.97840.23360.048*
H18C0.29700.91520.27030.048*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0255 (5)0.0281 (5)0.0283 (5)0.0044 (4)0.0000 (4)0.0009 (4)
O20.0249 (5)0.0407 (6)0.0287 (5)0.0018 (4)0.0044 (4)0.0051 (4)
O30.0373 (6)0.0240 (5)0.0376 (5)0.0030 (4)0.0068 (4)0.0011 (4)
O40.0247 (5)0.0246 (5)0.0269 (5)0.0023 (4)0.0013 (4)0.0036 (4)
C10.0224 (6)0.0275 (7)0.0231 (6)0.0008 (6)0.0041 (5)0.0012 (5)
C20.0206 (6)0.0235 (7)0.0220 (6)0.0020 (5)0.0007 (5)0.0006 (5)
C30.0213 (6)0.0212 (6)0.0256 (6)0.0013 (5)0.0030 (5)0.0005 (5)
C40.0261 (7)0.0246 (7)0.0258 (6)0.0018 (6)0.0050 (5)0.0020 (5)
C50.0225 (6)0.0225 (6)0.0188 (6)0.0017 (5)0.0010 (5)0.0030 (5)
C60.0202 (6)0.0233 (6)0.0214 (6)0.0015 (5)0.0002 (5)0.0013 (5)
C70.0234 (6)0.0244 (7)0.0228 (6)0.0001 (5)0.0003 (5)0.0023 (5)
C80.0215 (6)0.0283 (7)0.0232 (6)0.0022 (6)0.0012 (5)0.0012 (5)
C90.0211 (6)0.0260 (7)0.0208 (6)0.0019 (5)0.0005 (5)0.0010 (5)
C100.0241 (7)0.0304 (7)0.0229 (6)0.0005 (6)0.0027 (5)0.0017 (5)
C110.0206 (6)0.0277 (7)0.0278 (7)0.0004 (5)0.0031 (5)0.0000 (5)
C120.0201 (6)0.0258 (7)0.0264 (6)0.0023 (5)0.0012 (5)0.0004 (5)
C130.0217 (6)0.0236 (7)0.0231 (6)0.0005 (5)0.0004 (5)0.0009 (5)
C140.0209 (6)0.0272 (7)0.0251 (6)0.0041 (5)0.0036 (5)0.0010 (5)
C150.0263 (7)0.0347 (8)0.0233 (6)0.0018 (6)0.0001 (5)0.0019 (6)
C160.0299 (7)0.0363 (8)0.0285 (7)0.0001 (6)0.0015 (6)0.0073 (6)
C170.0305 (7)0.0293 (8)0.0327 (7)0.0069 (6)0.0078 (6)0.0033 (6)
C180.0313 (7)0.0328 (8)0.0315 (7)0.0004 (6)0.0007 (6)0.0099 (6)
Geometric parameters (Å, º) top
O1—C41.3856 (16)C11—C121.5253 (18)
O1—C11.4136 (16)C11—H11A0.9900
O2—C11.1945 (15)C11—H11B0.9900
O3—C41.2026 (16)C12—C131.5421 (17)
O4—C71.3652 (15)C12—H12A0.9900
O4—C81.3905 (15)C12—H12B0.9900
C1—C21.4748 (17)C13—H13A0.9900
C2—C51.3715 (18)C13—H13B0.9900
C2—C31.4704 (17)C14—C151.4979 (19)
C3—C141.3544 (17)C14—C161.5064 (18)
C3—C41.4766 (18)C15—H15A0.9800
C5—C61.4608 (17)C15—H15B0.9800
C5—C131.5124 (17)C15—H15C0.9800
C6—C71.3653 (18)C16—H16A0.9800
C6—C91.4534 (17)C16—H16B0.9800
C7—C145.1143 (18)C16—H16C0.9800
C7—C171.4795 (18)C17—H17A0.9800
C8—C91.3477 (18)C17—H17B0.9800
C8—C181.4859 (18)C17—H17C0.9800
C9—C101.4996 (18)C18—H18A0.9800
C10—C111.5220 (18)C18—H18B0.9800
C10—H10A0.9900C18—H18C0.9800
C10—H10B0.9900
C4—O1—C1110.60 (10)H11A—C11—H11B107.7
C7—O4—C8107.23 (10)C11—C12—C13116.52 (11)
O2—C1—O1118.29 (12)C11—C12—H12A108.2
O2—C1—C2133.96 (13)C13—C12—H12A108.2
O1—C1—C2107.60 (11)C11—C12—H12B108.2
C5—C2—C3129.80 (12)C13—C12—H12B108.2
C5—C2—C1122.94 (11)H12A—C12—H12B107.3
C3—C2—C1105.86 (11)C5—C13—C12115.08 (10)
C14—C3—C2129.49 (12)C5—C13—H13A108.5
C14—C3—C4121.94 (12)C12—C13—H13A108.5
C2—C3—C4105.96 (11)C5—C13—H13B108.5
O3—C4—O1119.70 (12)C12—C13—H13B108.5
O3—C4—C3131.79 (13)H13A—C13—H13B107.5
O1—C4—C3108.35 (11)C3—C14—C15122.27 (12)
C2—C5—C6121.49 (11)C3—C14—C16122.21 (12)
C2—C5—C13120.71 (12)C15—C14—C16115.42 (11)
C6—C5—C13117.76 (11)C14—C15—H15A109.5
C7—C6—C9106.48 (11)C14—C15—H15B109.5
C7—C6—C5123.63 (11)H15A—C15—H15B109.5
C9—C6—C5129.26 (11)C14—C15—H15C109.5
O4—C7—C6109.89 (11)H15A—C15—H15C109.5
O4—C7—C17114.98 (11)H15B—C15—H15C109.5
C6—C7—C17135.07 (12)C14—C16—H16A109.5
C9—C8—O4110.12 (11)C14—C16—H16B109.5
C9—C8—C18134.95 (12)H16A—C16—H16B109.5
O4—C8—C18114.93 (11)C14—C16—H16C109.5
C8—C9—C6106.28 (11)H16A—C16—H16C109.5
C8—C9—C10126.49 (12)H16B—C16—H16C109.5
C6—C9—C10127.18 (12)C7—C17—H17A109.5
C9—C10—C11113.87 (10)C7—C17—H17B109.5
C9—C10—H10A108.8H17A—C17—H17B109.5
C11—C10—H10A108.8C7—C17—H17C109.5
C9—C10—H10B108.8H17A—C17—H17C109.5
C11—C10—H10B108.8H17B—C17—H17C109.5
H10A—C10—H10B107.7C8—C18—H18A109.5
C10—C11—C12113.42 (11)C8—C18—H18B109.5
C10—C11—H11A108.9H18A—C18—H18B109.5
C12—C11—H11A108.9C8—C18—H18C109.5
C10—C11—H11B108.9H18A—C18—H18C109.5
C12—C11—H11B108.9H18B—C18—H18C109.5
C2—C5—C6—C744.98 (18)C2—C5—C6—C9145.41 (13)
C3—C2—C5—C6163.10 (12)C1—C2—C3—C14148.71 (13)
C5—C2—C3—C1444.8 (2)
(III-E) 3-isopropylidene-4-[(E)-1-(5-methoxy-2-methyl-1-benzofuran-3- yl)ethylidene]tetrahydrofuran-2,5-dione top
Crystal data top
C19H18O5Z = 4
Mr = 326.33F(000) = 688
Triclinic, P1Dx = 1.355 Mg m3
a = 7.1750 (2) ÅMo Kα radiation, λ = 0.71073 Å
b = 12.0569 (2) ÅCell parameters from 28103 reflections
c = 19.9592 (4) Åθ = 2.9–27.5°
α = 103.8136 (12)°µ = 0.10 mm1
β = 91.1022 (13)°T = 100 K
γ = 106.5927 (12)°Fragment, colourless
V = 1599.77 (6) Å30.30 × 0.25 × 0.09 mm
Data collection top
KappaCCD
diffractometer
7318 independent reflections
Radiation source: fine-focus sealed tube5802 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.040
CCD scansθmax = 27.5°, θmin = 3.0°
Absorption correction: multi-scan
(DENZO and SCALEPACK; Otwinowski & Minor, 1997)
h = 99
Tmin = 0.971, Tmax = 0.991k = 1514
38746 measured reflectionsl = 2525
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.040Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.107H-atom parameters constrained
S = 1.03 w = 1/[σ2(Fo2) + (0.0575P)2 + 0.2713P]
where P = (Fo2 + 2Fc2)/3
7318 reflections(Δ/σ)max = 0.001
443 parametersΔρmax = 0.22 e Å3
0 restraintsΔρmin = 0.28 e Å3
Crystal data top
C19H18O5γ = 106.5927 (12)°
Mr = 326.33V = 1599.77 (6) Å3
Triclinic, P1Z = 4
a = 7.1750 (2) ÅMo Kα radiation
b = 12.0569 (2) ŵ = 0.10 mm1
c = 19.9592 (4) ÅT = 100 K
α = 103.8136 (12)°0.30 × 0.25 × 0.09 mm
β = 91.1022 (13)°
Data collection top
KappaCCD
diffractometer
7318 independent reflections
Absorption correction: multi-scan
(DENZO and SCALEPACK; Otwinowski & Minor, 1997)
5802 reflections with I > 2σ(I)
Tmin = 0.971, Tmax = 0.991Rint = 0.040
38746 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0400 restraints
wR(F2) = 0.107H-atom parameters constrained
S = 1.03Δρmax = 0.22 e Å3
7318 reflectionsΔρmin = 0.28 e Å3
443 parameters
Special details top

Experimental. General preparation of fulgides (I)–(III): a solution of diethyl isopropylidene succinate (15 mmol) in THF [tetrahydrofuran?] (15 ml) was cooled to 195 K and LDA (7.5 ml, 15 mmol; 2 M, THF/n-heptane/ethylbenzene) was added under an argon atmosphere. After stirring for 1 h the appropriate ketone (10 mmol) dissolved in THF (30 ml) was added via a syringe. The reaction mixture was allowed to warm to room temperature overnight and stirred for an additional 24 h. The reaction progress was monitored by TLC [thin layer chromatography?]. Afterwards the reaction mixture was acidified with aqueous HCl (2 M) and the aqueous layer was extracted with ethyl acetate (3 x 50 ml). The combined organic layers were washed with saturated aqueous NaCl solution, dried over MgSO4 and the solvent was removed in vacuo. The residue was dissolved in cyclohexane/ethyl acetate (7:3), filtered over silica gel and the solvent removed in vacuo again. The residue was dissolved in ethanol (60 ml) and a saturated aqueous solution of KOH (5 ml) was added. After stirring for 20 h at 343 K the reaction mixture was poured onto ice and acidified with aqueous HCl (2 M). The aqueous layer was extracted with ethyl acetate (3 x 50 ml) and the combined organic layers were washed with saturated aqueous NaCl, dried over MgSO4 and the solvent was removed in vacuo. The dark brown residue was dissolved in dichloromethane (50 ml) and N,N'-dicyclohexylcarbodiimide (4.13 g, 20 mmol) was added. After stirring for 48 h the reaction mixture was filtered over silica gel and the solvent was removed in vacuo. The products were purified by column chromatography and recrystallized from adapted solvents.

(III-E): yield 13% (recrystallized from diethyl ether); Rf=0.26 (cyclohexane/ethyl acetate 9:1); 1H NMR (500 MHz, CDCl3, 25 °C, CDCl3=7.24 p.p.m.) δ=1.12 (s, 3H; CH3), 2.23 (s, 6H; CH3), 2.72 (s, 3H; CH3), 3.79 (s, 3H; CH3), 6.70 (d, 4J(H,H)=2.5 Hz, 1H; Ar—H), 6.85 (dd, 3J(H,H)=9.4 Hz, 4J(H,H)=2.5 Hz, 1H; Ar—H), 7.29 p.p.m. (d, 3J(H,H)=9.4 Hz, 1H; Ar—H); 13C NMR (126 MHz, CDCl3, 25 °C, CDCl3=77.0 p.p.m.) δ=14.0, 22.0, 22.7, 26.7, 55.9, 102.8, 111.6, 112.9, 119.6, 120.8, 121.5, 126.5, 145.0, 148.9, 153.5, 155.5, 156.2, 163.0, 163.6 p.p.m.; MS (70 eV): m/z (%): 327 (22), 326 (100) [M+], 311 (43), 309 (12), 283 (20), 281 (12), 267 (41), 265 (15), 253 (13), 239 (17), 223 (11), 204 (11), 165 (11), 162 (21), 152 (12), 115 (13), 106 (12), 91 (12), 77 (10), 44 (12), 43 (16); HRMS (m/z) [M+] calcd for C19H18O5 + Na+: 349.10464; found 349.10480; calcd for (C19H18O5)2 + Na+: 675.22026; found 675.22007.

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.83247 (13)0.42934 (8)0.10941 (5)0.0278 (2)
O20.84769 (13)0.57350 (8)0.01315 (5)0.0276 (2)
O30.78118 (16)0.25524 (10)0.18915 (5)0.0395 (3)
O40.54766 (12)0.08759 (7)0.09187 (4)0.02121 (19)
O50.03222 (13)0.25903 (8)0.20856 (5)0.0249 (2)
O60.19367 (13)1.06123 (8)0.57325 (5)0.0270 (2)
O70.24410 (13)1.08504 (8)0.46656 (5)0.0286 (2)
O80.12701 (16)0.98909 (10)0.66622 (5)0.0371 (3)
O90.01193 (12)0.50256 (7)0.40880 (4)0.02073 (19)
O100.68627 (13)0.55086 (8)0.27943 (5)0.0271 (2)
C10.77789 (18)0.47028 (11)0.04341 (7)0.0229 (3)
C20.64341 (17)0.36724 (10)0.02416 (6)0.0194 (2)
C30.58961 (18)0.26948 (11)0.08837 (6)0.0212 (3)
C40.73649 (19)0.30723 (12)0.13588 (7)0.0261 (3)
C50.41913 (18)0.18098 (11)0.11029 (6)0.0211 (3)
C60.3731 (2)0.09948 (12)0.18220 (6)0.0264 (3)
H6A0.48710.11730.20850.040*
H6B0.26210.11190.20550.040*
H6C0.34000.01610.17950.040*
C70.25495 (18)0.16127 (11)0.06501 (7)0.0245 (3)
H7A0.26660.10320.03940.037*
H7B0.13000.13050.09380.037*
H7C0.26090.23720.03220.037*
C80.60882 (17)0.37010 (10)0.04286 (6)0.0191 (2)
C90.65576 (18)0.48588 (11)0.09897 (6)0.0217 (3)
H9A0.79600.51380.11380.033*
H9B0.58200.47240.13860.033*
H9C0.61970.54640.08090.033*
C100.54151 (17)0.26032 (10)0.06656 (6)0.0188 (2)
C110.39070 (17)0.23068 (10)0.11249 (6)0.0187 (2)
C120.24555 (17)0.28075 (11)0.13935 (6)0.0200 (2)
H120.23430.35240.13010.024*
C130.11888 (17)0.22168 (11)0.17993 (6)0.0209 (3)
C140.13627 (18)0.11643 (11)0.19469 (6)0.0224 (3)
H140.04990.07980.22400.027*
C150.27723 (18)0.06540 (11)0.16719 (6)0.0226 (3)
H150.28860.00640.17620.027*
C160.40091 (18)0.12450 (10)0.12591 (6)0.0203 (2)
C170.62971 (17)0.17192 (10)0.05623 (6)0.0193 (2)
C180.79861 (18)0.15372 (11)0.01844 (6)0.0222 (3)
H18A0.75160.09300.02550.033*
H18B0.88160.12690.04670.033*
H18C0.87430.22920.00920.033*
C190.0470 (2)0.37033 (12)0.19978 (7)0.0266 (3)
H19A0.07340.43410.22020.040*
H19B0.15810.38830.22290.040*
H19C0.06640.36510.15030.040*
C200.23237 (17)1.02088 (11)0.50498 (7)0.0225 (3)
C210.23856 (17)0.89626 (10)0.49370 (6)0.0199 (2)
C220.23080 (17)0.87166 (11)0.56294 (6)0.0212 (3)
C230.17559 (19)0.97184 (12)0.60832 (7)0.0257 (3)
C240.30070 (17)0.79572 (11)0.58899 (6)0.0217 (3)
C250.2977 (2)0.79252 (13)0.66383 (7)0.0291 (3)
H25A0.42980.83050.68740.044*
H25B0.25200.70920.66680.044*
H25C0.20950.83580.68610.044*
C260.39663 (18)0.71076 (11)0.54697 (7)0.0228 (3)
H26A0.30060.63160.53040.034*
H26B0.50400.70500.57580.034*
H26C0.44810.74010.50720.034*
C270.22750 (17)0.82663 (10)0.42822 (6)0.0195 (2)
C280.25997 (19)0.87850 (11)0.36601 (7)0.0238 (3)
H28A0.14760.90450.35560.036*
H28B0.27500.81740.32600.036*
H28C0.37840.94720.37610.036*
C290.17468 (17)0.69556 (10)0.41283 (6)0.0188 (2)
C300.27989 (18)0.61997 (10)0.37302 (6)0.0193 (2)
C310.45498 (18)0.64168 (11)0.34141 (6)0.0211 (2)
H310.52840.72040.34050.025*
C320.51657 (18)0.54338 (11)0.31157 (6)0.0214 (3)
C330.40928 (19)0.42672 (11)0.31314 (6)0.0228 (3)
H330.45570.36160.29200.027*
C340.23757 (18)0.40485 (11)0.34486 (6)0.0216 (3)
H340.16520.32640.34670.026*
C350.17672 (18)0.50393 (11)0.37380 (6)0.0199 (2)
C360.01579 (18)0.62109 (10)0.43240 (6)0.0198 (2)
C370.15005 (18)0.64132 (11)0.47109 (7)0.0225 (3)
H37A0.13810.62530.51660.034*
H37B0.27280.58760.44520.034*
H37C0.14920.72460.47720.034*
C380.7970 (2)0.66647 (12)0.27383 (7)0.0302 (3)
H38A0.71760.69740.24680.045*
H38B0.91430.66070.25060.045*
H38C0.83530.72080.32020.045*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0245 (5)0.0323 (5)0.0258 (5)0.0029 (4)0.0064 (4)0.0125 (4)
O20.0243 (5)0.0209 (5)0.0378 (5)0.0035 (4)0.0022 (4)0.0118 (4)
O30.0361 (6)0.0494 (6)0.0261 (5)0.0055 (5)0.0130 (4)0.0046 (5)
O40.0223 (4)0.0198 (4)0.0238 (4)0.0076 (3)0.0067 (3)0.0077 (3)
O50.0221 (5)0.0290 (5)0.0273 (5)0.0108 (4)0.0094 (4)0.0099 (4)
O60.0269 (5)0.0211 (4)0.0300 (5)0.0094 (4)0.0001 (4)0.0018 (4)
O70.0264 (5)0.0194 (4)0.0405 (6)0.0065 (4)0.0037 (4)0.0086 (4)
O80.0450 (6)0.0459 (6)0.0229 (5)0.0259 (5)0.0019 (4)0.0014 (4)
O90.0220 (4)0.0174 (4)0.0229 (4)0.0061 (3)0.0049 (3)0.0048 (3)
O100.0239 (5)0.0281 (5)0.0299 (5)0.0101 (4)0.0091 (4)0.0052 (4)
C10.0179 (6)0.0273 (7)0.0271 (6)0.0074 (5)0.0025 (5)0.0132 (5)
C20.0166 (6)0.0194 (6)0.0230 (6)0.0051 (5)0.0022 (5)0.0071 (5)
C30.0220 (6)0.0250 (6)0.0193 (6)0.0090 (5)0.0049 (5)0.0082 (5)
C40.0229 (6)0.0319 (7)0.0226 (6)0.0055 (5)0.0044 (5)0.0084 (5)
C50.0226 (6)0.0221 (6)0.0210 (6)0.0088 (5)0.0017 (5)0.0075 (5)
C60.0281 (7)0.0277 (7)0.0216 (6)0.0074 (5)0.0004 (5)0.0042 (5)
C70.0203 (6)0.0242 (6)0.0251 (6)0.0022 (5)0.0023 (5)0.0039 (5)
C80.0152 (6)0.0202 (6)0.0231 (6)0.0063 (4)0.0019 (4)0.0067 (5)
C90.0221 (6)0.0196 (6)0.0233 (6)0.0060 (5)0.0032 (5)0.0054 (5)
C100.0179 (6)0.0199 (6)0.0172 (5)0.0044 (5)0.0019 (4)0.0039 (5)
C110.0189 (6)0.0190 (6)0.0172 (5)0.0043 (4)0.0011 (4)0.0042 (5)
C120.0205 (6)0.0210 (6)0.0188 (6)0.0066 (5)0.0020 (5)0.0049 (5)
C130.0183 (6)0.0245 (6)0.0181 (6)0.0055 (5)0.0016 (5)0.0031 (5)
C140.0216 (6)0.0233 (6)0.0209 (6)0.0033 (5)0.0043 (5)0.0071 (5)
C150.0237 (6)0.0208 (6)0.0234 (6)0.0049 (5)0.0033 (5)0.0079 (5)
C160.0204 (6)0.0203 (6)0.0197 (6)0.0064 (5)0.0028 (5)0.0039 (5)
C170.0187 (6)0.0178 (5)0.0197 (6)0.0027 (4)0.0024 (5)0.0052 (5)
C180.0220 (6)0.0212 (6)0.0239 (6)0.0068 (5)0.0053 (5)0.0059 (5)
C190.0275 (7)0.0313 (7)0.0270 (7)0.0157 (6)0.0066 (5)0.0100 (6)
C200.0156 (6)0.0194 (6)0.0293 (6)0.0037 (5)0.0002 (5)0.0021 (5)
C210.0157 (6)0.0177 (6)0.0253 (6)0.0045 (4)0.0010 (5)0.0043 (5)
C220.0180 (6)0.0208 (6)0.0213 (6)0.0045 (5)0.0004 (5)0.0009 (5)
C230.0217 (6)0.0276 (7)0.0254 (7)0.0092 (5)0.0026 (5)0.0006 (5)
C240.0169 (6)0.0217 (6)0.0229 (6)0.0023 (5)0.0014 (5)0.0033 (5)
C250.0312 (7)0.0335 (7)0.0228 (6)0.0102 (6)0.0032 (5)0.0071 (6)
C260.0229 (6)0.0212 (6)0.0248 (6)0.0066 (5)0.0012 (5)0.0070 (5)
C270.0156 (6)0.0200 (6)0.0235 (6)0.0060 (4)0.0025 (5)0.0060 (5)
C280.0248 (6)0.0213 (6)0.0262 (6)0.0070 (5)0.0052 (5)0.0075 (5)
C290.0201 (6)0.0196 (6)0.0177 (5)0.0074 (5)0.0016 (4)0.0048 (5)
C300.0214 (6)0.0189 (6)0.0170 (5)0.0069 (5)0.0001 (5)0.0028 (5)
C310.0215 (6)0.0197 (6)0.0213 (6)0.0056 (5)0.0025 (5)0.0042 (5)
C320.0210 (6)0.0261 (6)0.0178 (6)0.0091 (5)0.0030 (5)0.0044 (5)
C330.0274 (7)0.0218 (6)0.0205 (6)0.0122 (5)0.0006 (5)0.0019 (5)
C340.0254 (6)0.0191 (6)0.0207 (6)0.0078 (5)0.0009 (5)0.0044 (5)
C350.0206 (6)0.0210 (6)0.0178 (5)0.0063 (5)0.0013 (5)0.0041 (5)
C360.0225 (6)0.0180 (6)0.0186 (6)0.0068 (5)0.0005 (5)0.0035 (5)
C370.0228 (6)0.0214 (6)0.0245 (6)0.0076 (5)0.0052 (5)0.0064 (5)
C380.0247 (7)0.0311 (7)0.0330 (7)0.0062 (6)0.0092 (6)0.0067 (6)
Geometric parameters (Å, º) top
O1—C11.3972 (15)C15—H150.9500
O1—C41.3987 (16)C17—C181.4811 (16)
O2—C11.1991 (15)C18—H18A0.9800
O3—C41.1983 (16)C18—H18B0.9800
O4—C171.3805 (14)C18—H18C0.9800
O4—C161.3853 (14)C19—H19A0.9800
O5—C131.3727 (14)C19—H19B0.9800
O5—C191.4268 (15)C19—H19C0.9800
O6—C201.3949 (16)C20—C211.4789 (17)
O6—C231.3973 (16)C21—C271.3614 (17)
O7—C201.2008 (16)C21—C221.4800 (17)
O8—C231.2009 (16)C22—C241.3564 (18)
O9—C351.3829 (14)C22—C231.4836 (17)
O9—C361.3858 (14)C24—C261.4970 (17)
O10—C321.3774 (15)C24—C251.5038 (17)
O10—C381.4256 (16)C24—C363.5403 (17)
C1—C21.4763 (16)C25—H25A0.9800
C2—C81.3592 (17)C25—H25B0.9800
C2—C31.4768 (17)C25—H25C0.9800
C3—C51.3554 (18)C26—H26A0.9800
C3—C41.4790 (17)C26—H26B0.9800
C5—C71.4982 (17)C26—H26C0.9800
C5—C61.5024 (17)C27—C291.4686 (16)
C5—C173.6629 (17)C27—C281.5119 (17)
C6—H6A0.9800C28—H28A0.9800
C6—H6B0.9800C28—H28B0.9800
C6—H6C0.9800C28—H28C0.9800
C7—H7A0.9800C29—C361.3632 (17)
C7—H7B0.9800C29—C301.4497 (16)
C7—H7C0.9800C30—C351.3875 (17)
C8—C101.4669 (16)C30—C311.4024 (17)
C8—C91.5122 (17)C31—C321.3881 (17)
C9—H9A0.9800C31—H310.9500
C9—H9B0.9800C32—C331.4055 (18)
C9—H9C0.9800C33—C341.3829 (18)
C10—C171.3654 (17)C33—H330.9500
C10—C111.4534 (16)C34—C351.3890 (17)
C11—C161.3901 (17)C34—H340.9500
C11—C121.4010 (16)C36—C371.4774 (16)
C12—C131.3869 (17)C37—H37A0.9800
C12—H120.9500C37—H37B0.9800
C13—C141.4072 (18)C37—H37C0.9800
C14—C151.3850 (18)C38—H38A0.9800
C14—H140.9500C38—H38B0.9800
C15—C161.3862 (17)C38—H38C0.9800
C1—O1—C4110.42 (9)O5—C19—H19C109.5
C17—O4—C16106.12 (9)H19A—C19—H19C109.5
C13—O5—C19116.75 (9)H19B—C19—H19C109.5
C20—O6—C23110.26 (9)O7—C20—O6118.97 (11)
C35—O9—C36106.03 (9)O7—C20—C21132.16 (12)
C32—O10—C38116.90 (10)O6—C20—C21108.73 (10)
O2—C1—O1118.97 (11)C27—C21—C20120.29 (11)
O2—C1—C2132.87 (12)C27—C21—C22133.53 (11)
O1—C1—C2108.09 (10)C20—C21—C22105.65 (10)
C8—C2—C1121.62 (11)C24—C22—C21130.98 (11)
C8—C2—C3132.19 (11)C24—C22—C23122.02 (11)
C1—C2—C3105.69 (10)C21—C22—C23105.27 (10)
C5—C3—C2129.69 (11)O8—C23—O6118.50 (12)
C5—C3—C4122.85 (11)O8—C23—C22133.05 (13)
C2—C3—C4105.08 (10)O6—C23—C22108.41 (10)
O3—C4—O1118.97 (12)C22—C24—C26123.43 (11)
O3—C4—C3133.00 (13)C22—C24—C25123.25 (11)
O1—C4—C3108.02 (10)C26—C24—C25113.27 (11)
C3—C5—C7121.93 (11)C24—C25—H25A109.5
C3—C5—C6123.77 (11)C24—C25—H25B109.5
C7—C5—C6114.22 (11)H25A—C25—H25B109.5
C5—C6—H6A109.5C24—C25—H25C109.5
C5—C6—H6B109.5H25A—C25—H25C109.5
H6A—C6—H6B109.5H25B—C25—H25C109.5
C5—C6—H6C109.5C24—C26—H26A109.5
H6A—C6—H6C109.5C24—C26—H26B109.5
H6B—C6—H6C109.5H26A—C26—H26B109.5
C5—C7—H7A109.5C24—C26—H26C109.5
C5—C7—H7B109.5H26A—C26—H26C109.5
H7A—C7—H7B109.5H26B—C26—H26C109.5
C5—C7—H7C109.5C21—C27—C29122.25 (11)
H7A—C7—H7C109.5C21—C27—C28122.29 (11)
H7B—C7—H7C109.5C29—C27—C28115.41 (10)
C2—C8—C10121.83 (11)C27—C28—H28A109.5
C2—C8—C9122.35 (11)C27—C28—H28B109.5
C10—C8—C9115.56 (10)H28A—C28—H28B109.5
C8—C9—H9A109.5C27—C28—H28C109.5
C8—C9—H9B109.5H28A—C28—H28C109.5
H9A—C9—H9B109.5H28B—C28—H28C109.5
C8—C9—H9C109.5C36—C29—C30106.59 (10)
H9A—C9—H9C109.5C36—C29—C27126.72 (11)
H9B—C9—H9C109.5C30—C29—C27126.69 (11)
C17—C10—C11106.31 (10)C35—C30—C31119.89 (11)
C17—C10—C8124.95 (11)C35—C30—C29105.56 (10)
C11—C10—C8128.23 (11)C31—C30—C29134.40 (11)
C16—C11—C12119.84 (11)C32—C31—C30117.25 (11)
C16—C11—C10105.59 (10)C32—C31—H31121.4
C12—C11—C10134.45 (11)C30—C31—H31121.4
C13—C12—C11117.45 (11)O10—C32—C31123.83 (11)
C13—C12—H12121.3O10—C32—C33114.46 (11)
C11—C12—H12121.3C31—C32—C33121.69 (11)
O5—C13—C12123.86 (11)C34—C33—C32121.34 (11)
O5—C13—C14114.50 (10)C34—C33—H33119.3
C12—C13—C14121.64 (11)C32—C33—H33119.3
C15—C14—C13121.09 (11)C33—C34—C35116.29 (11)
C15—C14—H14119.5C33—C34—H34121.9
C13—C14—H14119.5C35—C34—H34121.9
C14—C15—C16116.59 (11)O9—C35—C30110.65 (10)
C14—C15—H15121.7O9—C35—C34125.79 (11)
C16—C15—H15121.7C30—C35—C34123.52 (11)
O4—C16—C15126.11 (11)C29—C36—O9111.11 (10)
O4—C16—C11110.54 (10)C29—C36—C37133.34 (11)
C15—C16—C11123.34 (11)O9—C36—C37115.53 (10)
C10—C17—O4111.44 (10)C36—C37—H37A109.5
C10—C17—C18132.88 (11)C36—C37—H37B109.5
O4—C17—C18115.58 (10)H37A—C37—H37B109.5
C17—C18—H18A109.5C36—C37—H37C109.5
C17—C18—H18B109.5H37A—C37—H37C109.5
H18A—C18—H18B109.5H37B—C37—H37C109.5
C17—C18—H18C109.5O10—C38—H38A109.5
H18A—C18—H18C109.5O10—C38—H38B109.5
H18B—C18—H18C109.5H38A—C38—H38B109.5
O5—C19—H19A109.5O10—C38—H38C109.5
O5—C19—H19B109.5H38A—C38—H38C109.5
H19A—C19—H19B109.5H38B—C38—H38C109.5
C2—C8—C10—C1752.48 (18)C21—C27—C29—C3651.58 (19)
C3—C2—C8—C1014.7 (2)C22—C21—C27—C299.0 (2)
C8—C2—C3—C541.9 (2)C27—C21—C22—C2436.3 (2)
C2—C8—C10—C11136.83 (13)C21—C27—C29—C30129.36 (13)
C1—C2—C3—C5146.29 (13)C20—C21—C22—C24152.36 (13)
(III-Z) 3-isopropylidene-4-[(Z)-1-(5-methoxy-2-methyl-1-benzofuran-3- yl)ethylidene]tetrahydrofuran-2,5-dione top
Crystal data top
C19H18O5F(000) = 1376
Mr = 326.33Dx = 1.370 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 31599 reflections
a = 26.5923 (4) Åθ = 2.9–27.5°
b = 8.6140 (1) ŵ = 0.10 mm1
c = 15.3550 (2) ÅT = 100 K
β = 115.8482 (8)°Fragment, colourless
V = 3165.41 (7) Å30.30 × 0.25 × 0.10 mm
Z = 8
Data collection top
KappaCCD
diffractometer
3606 independent reflections
Radiation source: fine-focus sealed tube3205 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.033
CCD scansθmax = 27.5°, θmin = 3.0°
Absorption correction: multi-scan
(DENZO and SCALEPACK; Otwinowski & Minor, 1997)
h = 3334
Tmin = 0.971, Tmax = 0.990k = 1111
54136 measured reflectionsl = 1919
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.034Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.091H-atom parameters constrained
S = 1.06 w = 1/[σ2(Fo2) + (0.0494P)2 + 1.6756P]
where P = (Fo2 + 2Fc2)/3
3606 reflections(Δ/σ)max < 0.001
222 parametersΔρmax = 0.25 e Å3
0 restraintsΔρmin = 0.22 e Å3
Crystal data top
C19H18O5V = 3165.41 (7) Å3
Mr = 326.33Z = 8
Monoclinic, C2/cMo Kα radiation
a = 26.5923 (4) ŵ = 0.10 mm1
b = 8.6140 (1) ÅT = 100 K
c = 15.3550 (2) Å0.30 × 0.25 × 0.10 mm
β = 115.8482 (8)°
Data collection top
KappaCCD
diffractometer
3606 independent reflections
Absorption correction: multi-scan
(DENZO and SCALEPACK; Otwinowski & Minor, 1997)
3205 reflections with I > 2σ(I)
Tmin = 0.971, Tmax = 0.990Rint = 0.033
54136 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0340 restraints
wR(F2) = 0.091H-atom parameters constrained
S = 1.06Δρmax = 0.25 e Å3
3606 reflectionsΔρmin = 0.22 e Å3
222 parameters
Special details top

Experimental. General preparation of fulgides (I)–(III): a solution of diethyl isopropylidene succinate (15 mmol) in THF [tetrahydrofuran?] (15 ml) was cooled to 195 K and LDA (7.5 ml, 15 mmol; 2 M, THF/n-heptane/ethylbenzene) was added under an argon atmosphere. After stirring for 1 h the appropriate ketone (10 mmol) dissolved in THF (30 ml) was added via a syringe. The reaction mixture was allowed to warm to room temperature overnight and stirred for an additional 24 h. The reaction progress was monitored by TLC [thin layer chromatography?]. Afterwards the reaction mixture was acidified with aqueous HCl (2 M) and the aqueous layer was extracted with ethyl acetate (3 x 50 ml). The combined organic layers were washed with saturated aqueous NaCl solution, dried over MgSO4 and the solvent was removed in vacuo. The residue was dissolved in cyclohexane/ethyl acetate (7:3), filtered over silica gel and the solvent removed in vacuo again. The residue was dissolved in ethanol (60 ml) and a saturated aqueous solution of KOH (5 ml) was added. After stirring for 20 h at 343 K the reaction mixture was poured onto ice and acidified with aqueous HCl (2 M). The aqueous layer was extracted with ethyl acetate (3 x 50 ml) and the combined organic layers were washed with saturated aqueous NaCl, dried over MgSO4 and the solvent was removed in vacuo. The dark brown residue was dissolved in dichloromethane (50 ml) and N,N'-dicyclohexylcarbodiimide (4.13 g, 20 mmol) was added. After stirring for 48 h the reaction mixture was filtered over silica gel and the solvent was removed in vacuo. The products were purified by column chromatography and recrystallized from adapted solvents.

(III-Z): ield 10% (recrystallized from ethanol); Rf=0.11 (cyclohexane/ethyl acetate 9:1); 1H NMR (500 MHz, CDCl3, 25 °C, CDCl3=7.24 p.p.m.) δ=2.04 (s, 3H; CH3), 2.28 (s, 3H, CH3), 2.36 (s, 3H, CH3), 2.46 (s, 3H, CH3), 3.80 (s, 3H, CH3), 6.83 (m, 2H, Ar—H), 7.31 p.p.m. (d, 3J(H,H)=8.8 Hz, 1H, Ar—H); 13C NMR (126 MHz, CDCl3, 25 °C, CDCl3=77.0 p.p.m.) δ=13.6, 22.4, 24.0, 27.2, 66.0, 103.0, 111.6, 111.7, 114.9, 121.3, 122.8, 127.6, 143.8, 148.9, 154.3, 156.0, 157.2, 160.9, 163.2 p.p.m.; MS (70 eV): m/z (%): 327 (21), 326 (100) [M+], 311 (37) [M - CH3+], 309 (11), 283 (18), 281 (10), 267 (67), 265 (12), 253 (12) 239 (20), 227 (15), 204 (10), 162 (19), 152 (10), 115 (10); HRMS (m/z) [M+] calcd for C19H18O5: 326.11542; found 326.11390.

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
O10.43332 (3)0.28489 (9)0.50657 (5)0.02243 (18)
O20.36292 (3)0.28865 (9)0.54967 (5)0.02397 (18)
O30.49219 (3)0.32877 (9)0.43999 (6)0.02698 (19)
O40.25671 (3)0.56512 (8)0.58670 (5)0.01936 (17)
O50.41157 (3)0.96371 (9)0.84152 (5)0.02463 (18)
C10.38619 (4)0.35342 (12)0.50851 (7)0.0191 (2)
C20.37786 (4)0.50603 (12)0.45912 (7)0.0168 (2)
C30.41158 (4)0.49955 (12)0.40447 (7)0.0176 (2)
C40.45132 (4)0.37032 (12)0.44801 (7)0.0208 (2)
C50.40443 (4)0.57194 (12)0.32176 (7)0.0183 (2)
C60.44539 (4)0.55653 (13)0.27886 (8)0.0235 (2)
H6A0.43390.62410.22210.035*0.50
H6B0.44620.44850.25950.035*0.50
H6C0.48270.58700.32710.035*0.50
H6D0.47470.48230.31700.035*0.50
H6E0.46230.65790.27960.035*0.50
H6F0.42590.51940.21200.035*0.50
C70.35396 (4)0.66927 (12)0.26469 (7)0.0202 (2)
H7A0.32440.64480.28440.030*
H7B0.34070.64730.19560.030*
H7C0.36380.77940.27680.030*
C80.35857 (4)0.63356 (12)0.48736 (7)0.0168 (2)
C90.37121 (4)0.79532 (11)0.46521 (7)0.0193 (2)
H9A0.40530.79380.45560.029*
H9B0.37660.86430.51940.029*
H9C0.34000.83320.40630.029*
C100.32634 (4)0.62310 (11)0.54440 (7)0.0170 (2)
C110.33636 (4)0.70789 (11)0.63227 (7)0.0175 (2)
C120.37859 (4)0.80759 (11)0.69452 (7)0.0187 (2)
H120.40940.83480.68190.022*
C130.37377 (4)0.86504 (12)0.77526 (7)0.0201 (2)
C140.32842 (4)0.82390 (12)0.79484 (7)0.0217 (2)
H140.32590.86650.84980.026*
C150.28751 (4)0.72235 (12)0.73519 (7)0.0209 (2)
H150.25730.69210.74880.025*
C160.29269 (4)0.66695 (12)0.65469 (7)0.0184 (2)
C170.27817 (4)0.54146 (12)0.52062 (7)0.0181 (2)
C180.24448 (4)0.44074 (12)0.43702 (7)0.0211 (2)
H18A0.24610.48110.37860.032*
H18B0.20560.43970.42760.032*
H18C0.25950.33490.44960.032*
C190.46033 (5)1.00277 (14)0.82939 (9)0.0290 (3)
H19A0.48090.90780.83030.043*
H19B0.48431.07130.88220.043*
H19C0.44931.05600.76730.043*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0220 (4)0.0213 (4)0.0212 (4)0.0046 (3)0.0069 (3)0.0002 (3)
O20.0323 (4)0.0203 (4)0.0217 (4)0.0005 (3)0.0140 (3)0.0022 (3)
O30.0166 (4)0.0285 (4)0.0335 (4)0.0011 (3)0.0087 (3)0.0097 (3)
O40.0185 (3)0.0228 (4)0.0189 (3)0.0012 (3)0.0101 (3)0.0022 (3)
O50.0306 (4)0.0219 (4)0.0203 (4)0.0003 (3)0.0101 (3)0.0036 (3)
C10.0207 (5)0.0188 (5)0.0158 (4)0.0012 (4)0.0060 (4)0.0025 (4)
C20.0157 (4)0.0190 (5)0.0147 (4)0.0014 (4)0.0057 (4)0.0009 (3)
C30.0147 (4)0.0192 (5)0.0186 (5)0.0014 (4)0.0071 (4)0.0047 (4)
C40.0171 (5)0.0224 (5)0.0196 (5)0.0017 (4)0.0050 (4)0.0068 (4)
C50.0172 (5)0.0197 (5)0.0193 (5)0.0048 (4)0.0092 (4)0.0059 (4)
C60.0218 (5)0.0292 (6)0.0243 (5)0.0038 (4)0.0147 (4)0.0048 (4)
C70.0211 (5)0.0219 (5)0.0185 (5)0.0016 (4)0.0096 (4)0.0006 (4)
C80.0158 (4)0.0196 (5)0.0147 (4)0.0002 (4)0.0063 (4)0.0006 (4)
C90.0232 (5)0.0177 (5)0.0202 (5)0.0007 (4)0.0123 (4)0.0006 (4)
C100.0196 (5)0.0163 (5)0.0164 (4)0.0024 (4)0.0088 (4)0.0016 (3)
C110.0201 (5)0.0172 (5)0.0169 (4)0.0048 (4)0.0096 (4)0.0032 (4)
C120.0210 (5)0.0179 (5)0.0187 (5)0.0024 (4)0.0100 (4)0.0016 (4)
C130.0244 (5)0.0166 (5)0.0175 (4)0.0050 (4)0.0074 (4)0.0015 (4)
C140.0282 (5)0.0225 (5)0.0166 (5)0.0096 (4)0.0118 (4)0.0036 (4)
C150.0220 (5)0.0243 (5)0.0199 (5)0.0077 (4)0.0124 (4)0.0062 (4)
C160.0187 (5)0.0189 (5)0.0177 (5)0.0037 (4)0.0081 (4)0.0037 (4)
C170.0199 (5)0.0187 (5)0.0170 (4)0.0034 (4)0.0092 (4)0.0040 (4)
C180.0219 (5)0.0208 (5)0.0197 (5)0.0011 (4)0.0080 (4)0.0020 (4)
C190.0326 (6)0.0238 (6)0.0284 (6)0.0048 (5)0.0113 (5)0.0028 (4)
Geometric parameters (Å, º) top
O1—C11.3974 (12)C7—H7C0.9800
O1—C41.3979 (13)C8—C101.4712 (13)
O2—C11.1977 (13)C8—C91.5066 (13)
O3—C41.2006 (13)C9—H9A0.9800
O4—C171.3791 (12)C9—H9B0.9800
O4—C161.3797 (12)C9—H9C0.9800
O5—C131.3698 (13)C10—C171.3641 (14)
O5—C191.4282 (14)C10—C111.4530 (13)
C1—C21.4853 (14)C11—C161.3929 (14)
C2—C81.3609 (14)C11—C121.4059 (14)
C2—C31.4722 (13)C12—C131.3918 (14)
C3—C51.3517 (14)C12—H120.9500
C3—C41.4788 (14)C13—C141.4093 (15)
C5—C71.4989 (14)C14—C151.3852 (16)
C5—C61.5047 (13)C14—H140.9500
C5—C175.4409 (14)C15—C161.3868 (14)
C6—H6A0.9800C15—H150.9500
C6—H6B0.9800C17—C181.4835 (14)
C6—H6C0.9800C18—H18A0.9800
C6—H6D0.9800C18—H18B0.9800
C6—H6E0.9800C18—H18C0.9800
C6—H6F0.9800C19—H19A0.9800
C7—H7A0.9800C19—H19B0.9800
C7—H7B0.9800C19—H19C0.9800
C1—O1—C4110.68 (8)C2—C8—C10122.59 (9)
C17—O4—C16106.13 (8)C2—C8—C9121.50 (9)
C13—O5—C19117.60 (8)C10—C8—C9115.86 (8)
O2—C1—O1119.28 (9)C8—C9—H9A109.5
O2—C1—C2133.27 (9)C8—C9—H9B109.5
O1—C1—C2107.36 (8)H9A—C9—H9B109.5
C8—C2—C3128.33 (9)C8—C9—H9C109.5
C8—C2—C1123.01 (9)H9A—C9—H9C109.5
C3—C2—C1105.38 (8)H9B—C9—H9C109.5
C5—C3—C2130.30 (9)C17—C10—C11106.16 (8)
C5—C3—C4123.51 (9)C17—C10—C8126.51 (9)
C2—C3—C4105.29 (8)C11—C10—C8127.12 (9)
O3—C4—O1119.22 (10)C16—C11—C12119.44 (9)
O3—C4—C3132.73 (10)C16—C11—C10105.50 (9)
O1—C4—C3108.03 (8)C12—C11—C10135.00 (9)
C3—C5—C7122.05 (9)C13—C12—C11117.79 (9)
C3—C5—C6122.58 (9)C13—C12—H12121.1
C7—C5—C6115.34 (9)C11—C12—H12121.1
C5—C6—H6A109.5O5—C13—C12124.02 (10)
C5—C6—H6B109.5O5—C13—C14114.63 (9)
H6A—C6—H6B109.5C12—C13—C14121.36 (10)
C5—C6—H6C109.5C15—C14—C13121.08 (9)
H6A—C6—H6C109.5C15—C14—H14119.5
H6B—C6—H6C109.5C13—C14—H14119.5
C5—C6—H6D109.5C14—C15—C16116.87 (9)
H6A—C6—H6D141.1C14—C15—H15121.6
H6B—C6—H6D56.3C16—C15—H15121.6
H6C—C6—H6D56.3O4—C16—C15125.99 (9)
C5—C6—H6E109.5O4—C16—C11110.59 (8)
H6A—C6—H6E56.3C15—C16—C11123.42 (10)
H6B—C6—H6E141.1C10—C17—O4111.62 (9)
H6C—C6—H6E56.3C10—C17—C18132.50 (9)
H6D—C6—H6E109.5O4—C17—C18115.82 (9)
C5—C6—H6F109.5C17—C18—H18A109.5
H6A—C6—H6F56.3C17—C18—H18B109.5
H6B—C6—H6F56.3H18A—C18—H18B109.5
H6C—C6—H6F141.1C17—C18—H18C109.5
H6D—C6—H6F109.5H18A—C18—H18C109.5
H6E—C6—H6F109.5H18B—C18—H18C109.5
C5—C7—H7A109.5O5—C19—H19A109.5
C5—C7—H7B109.5O5—C19—H19B109.5
H7A—C7—H7B109.5H19A—C19—H19B109.5
C5—C7—H7C109.5O5—C19—H19C109.5
H7A—C7—H7C109.5H19A—C19—H19C109.5
H7B—C7—H7C109.5H19B—C19—H19C109.5
C2—C8—C10—C1755.72 (15)C2—C8—C10—C11130.31 (11)
C3—C2—C8—C10178.29 (9)C1—C2—C3—C5151.31 (10)
C8—C2—C3—C549.02 (16)

Experimental details

(I-E)(II-E)(II-Z)(III-E)
Crystal data
Chemical formulaC17H18O4C18H20O4C18H20O4C19H18O5
Mr286.31300.34300.34326.33
Crystal system, space groupMonoclinic, P21/nMonoclinic, P21/nOrthorhombic, PbcaTriclinic, P1
Temperature (K)100100100100
a, b, c (Å)8.7142 (2), 12.0207 (3), 13.9102 (4)9.1881 (2), 12.0022 (3), 13.7215 (3)8.7024 (2), 12.8964 (4), 26.9492 (7)7.1750 (2), 12.0569 (2), 19.9592 (4)
α, β, γ (°)90, 100.9737 (18), 9090, 100.4329 (13), 9090, 90, 90103.8136 (12), 91.1022 (13), 106.5927 (12)
V3)1430.46 (6)1488.16 (6)3024.50 (14)1599.77 (6)
Z4484
Radiation typeMo KαMo KαMo KαMo Kα
µ (mm1)0.090.090.090.10
Crystal size (mm)0.27 × 0.12 × 0.100.30 × 0.30 × 0.200.30 × 0.30 × 0.260.30 × 0.25 × 0.09
Data collection
DiffractometerKappaCCD
diffractometer
KappaCCD
diffractometer
KappaCCD
diffractometer
KappaCCD
diffractometer
Absorption correctionMulti-scan
(DENZO and SCALEPACK; Otwinowski & Minor, 1997)
Multi-scan
(DENZO and SCALEPACK; Otwinowski & Minor, 1997)
Multi-scan
(DENZO and SCALEPACK; Otwinowski & Minor, 1997)
Multi-scan
(DENZO and SCALEPACK; Otwinowski & Minor, 1997)
Tmin, Tmax0.975, 0.9910.972, 0.9820.973, 0.9760.971, 0.991
No. of measured, independent and
observed [I > 2σ(I)] reflections
33163, 3278, 2810 28601, 3402, 2822 29108, 3444, 2657 38746, 7318, 5802
Rint0.0440.0370.0630.040
(sin θ/λ)max1)0.6490.6490.6480.650
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.037, 0.099, 1.02 0.035, 0.091, 1.06 0.038, 0.097, 1.03 0.040, 0.107, 1.03
No. of reflections3278340234447318
No. of parameters194203203443
H-atom treatmentH-atom parameters constrainedH-atom parameters constrainedH-atom parameters constrainedH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.26, 0.210.24, 0.220.21, 0.190.22, 0.28


(III-Z)
Crystal data
Chemical formulaC19H18O5
Mr326.33
Crystal system, space groupMonoclinic, C2/c
Temperature (K)100
a, b, c (Å)26.5923 (4), 8.6140 (1), 15.3550 (2)
α, β, γ (°)90, 115.8482 (8), 90
V3)3165.41 (7)
Z8
Radiation typeMo Kα
µ (mm1)0.10
Crystal size (mm)0.30 × 0.25 × 0.10
Data collection
DiffractometerKappaCCD
diffractometer
Absorption correctionMulti-scan
(DENZO and SCALEPACK; Otwinowski & Minor, 1997)
Tmin, Tmax0.971, 0.990
No. of measured, independent and
observed [I > 2σ(I)] reflections
54136, 3606, 3205
Rint0.033
(sin θ/λ)max1)0.649
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.034, 0.091, 1.06
No. of reflections3606
No. of parameters222
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.25, 0.22

Computer programs: COLLECT (Bruker, 2004), SCALEPACK (Otwinowski & Minor, 1997), SCALEPACK and DENZO (Otwinowski & Minor, 1997), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL-Plus (Sheldrick, 2008).

Selected bond lengths, angles and torsion angles of compounds (I)–(III) (Å, °) top
(I-E)(II-E)(III-Ea)(III-Eb)(II-Z)(III-Z)
ab1.3725 (15)1.3679 (15)1.3654 (17)1.3632 (17)1.3653 (18)1.3641 (14)
bc1.4507 (16)1.4609 (15)1.4669 (16)1.4686 (16)1.4608 (17)1.4712 (13)
cd1.3682 (15)1.3661 (15)1.3592 (17)1.3614 (17)1.3715 (18)1.3609 (14)
de1.4721 (15)1.4761 (15)1.4768 (17)1.4800 (17)1.4704 (17)1.4722 (13)
ef1.3559 (15)1.3552 (16)1.3554 (18)1.3564 (18)1.3544 (17)1.3517 (14)
fa3.5482 (15)3.5594 (15)3.6629 (17)3.5403 (17)5.1143 (18)5.4409 (14)
abc131.14 (10)128.62 (10)124.95 (11)126.72 (11)123.63 (11)126.51 (9)
bcd126.50 (10)125.58 (10)121.83 (11)122.25 (11)121.49 (11)122.59 (9)
cde132.48 (10)132.98 (10)132.19 (11)133.53 (11)129.80 (12)128.33 (9)
def129.11 (10)129.41 (10)129.69 (11)130.98 (11)129.49 (12)130.30 (9)
abcd28.51 (18)-37.86 (17)52.48 (18)51.58 (19)44.98 (18)-55.72 (15)
bcde16.47 (19)-10.38 (19)14.70 (2)9.00 (2)-163.10 (12)-178.29 (9)
cdef41.06 (19)-44.14 (19)41.90 (2)36.30 (2)44.80 (2)-49.02 (16)
gbcd-161.82 (10)151.11 (11)-136.83 (13)-129.36 (13)-145.41 (13)130.31 (11)
hdef-147.93 (11)144.83 (11)-146.29 (13)-152.36 (13)-148.71 (13)151.31 (10)
 

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