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A completely novel and direct route towards the synthesis of the natural sesquiterpenes α-cedrene and β-cedrene delivered the compounds (3β,3aβ,7β)-(±)-6,6-ethyl­ene­dioxy-3,8,8-tri­methyl-2,3,3a,4,5,6,7,8-octa­hydro-3a,7-methano­azulen-2-one, C16H22O3, and (3β,3aβ,7β,8aα)-(±)-6,6-ethyl­ene­dioxy-3,8,8-tri­methyl-1,2,3,3a,4,5,6,7,8,8a-deca­hydro-3a,7-methano­azulen-2-one, C16H24O3, at key stages of the preparative programme. Structural elucidation showed the latter compound to have added an H atom to the same face of the cyclo­pentenone ring as that occupied by the methyl substituent, and also allowed correct isomer identification for further reaction.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270101013336/gd1172sup1.cif
Contains datablocks global, IV, IIIa

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270101013336/gd1172IIIasup2.hkl
Contains datablock IIIa

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270101013336/gd1172IVsup3.hkl
Contains datablock IV

CCDC references: 173943; 173945

Comment top

In order to extend and illustrate our endeavours to develop further the efficiency (Kennedy et al., 2000; Ford et al., 2000) and applicability (Donkervoort et al., 1996) of the Khand cyclization reaction, we sought to utilize this annulation process strategically within routes towards the naturally ocurring sesquiterpenes α-cedrene, (Ia), and β-cedrene, (Ib). It was envisaged that use of these organocobalt-mediated methods would establish a direct and efficient pathway for the synthesis of the structurally demanding [5.3.1.01,5] tricyclic carbon skeleton of this family of natural species.

The cyclization precursors (IIa)/(IIb), prepared as an inseparable 2:1 mixture of geometric isomers, were employed in the key intramolecular Khand cyclization, and the products (IIIa) and (IIIb) were isolated in an excellent optimum combined yield of 95% (Kerr et al., 2001). Following separation, NMR spectroscopic studies could not fully identify each individual product with respect to the methyl group stereochemistry adjacent to the cyclopentenone carbonyl. Accordingly, the major component, (IIIa), was recrystallized and structural elucidation revealed the stereochemistry shown in Fig. 1. As this was not the required isomer, we were able to concentrate our synthetic endeavours on the tricyclic species, (IIIb), which was hydrogenated to give compound (IV), as shown in Fig. 2. In addition to showing the stereochemistry of the methyl group, the structure of (IV) also shows that the H atom introduced at the ring junction is syn to the methyl. Pleasingly, this stereochemical outcome was that desired for the continuation of the total synthesis programme. The crystal structure analyses of compounds (IIIa) and (IV) are presented here. \sch

Both structures (IIIa) and (IV) are comprised of discrete molecules, with all intermolecular distances being equal to at least the sum of van der Waal's radii. Interestingly, (IV) crystallizes in the chiral space group P21, raising the possibility of resolving the racemic mechanical mixture of crystals by utilizing seeding techniques.

The main differences in geometry between the two compounds are, as expected, centred around the double bond found in (IIIa) but not (IV). Not only is this C2—C3 bond shorter in (IIIa), but conjugation to the carbonyl group also causes significant changes to the C1—C2 and C1O1 distances [1.328 (3), 1.471 (3) and 1.221 (2) Å, respectively, for (IIIa), and 1.533 (2), 1.513 (3) and 1.210 (2) Å, respectively, for (IV)]. The presence of an sp2 hybridized atom at C3 also leads to a shortening of the C3—C4 and C3—C7 bonds. This shortening is more pronounced for C3—C4, which is within the cyclopentene ring, than it is for the aliphatic C3—C7 bond (see Tables 1 and 2). The bond lengths of the acetal group in (IIIa) are artificially shortened by a considerable degree of rotational motion (Fig. 1). A search of the Cambridge Structural Database (Release?; Allen & Kennard, 1993) found no cedrane-based fragments with a double bond such as that in (IIIa). However, several saturated analogues of (IV) were found, though none with a similarly placed ketone functionality. These gave geometric parameters consistent with those found for (IV) (for typical examples see Chen & Chang, 1996; Karlsson et al., 1973; Khan et al., 1985).

The conformation of the cedrene tricyclic skeleton is also affected by the introduction of an sp2 atom at C3. Least changed is the six-membered ring C4/C9/C8/C12/C11/C10, which adopts a chair conformation in both compounds. The planarity forced upon C2, C3, C4 and C7 in (IIIa) by the sp2 atom C3 is not perfect, as C3 lies slightly above the plane of the other three atoms, but it still has a marked effect on the five-membered rings C1/C2/C3/C4/C5 (ring A) and C3/C4/C9/C8/C7 (ring B). In (IIIa), there are two torsion angles around ring A that approach planarity [C1—C2—C3—C4 7.0 (3) and C3—C2—C1—C5 6.5 (2)°], which means that atoms C4 and C5 are twisted furthest from the ring plane. The torsion angles about ring A in (IV) show both an overall greater deviation from planarity (Table 2) and that C1 and C2 are the atoms twisted furthest out of the plane. The torsion angles about ring B for the two structures show that for both (IIIa) and (IV) the C4—C3—C7—C8 angle is flattest, but only for (IIIa) does it truly approach planarity [4.2 (3) and 11.24 (16)°, respectively]. The flattened conformation of (IIIa) leaves the methyl groups of C13 and C14 staggered with respect to C2 [C2—C3—C7—C13 57.0 (3)°], whilst in (IV), the methyl group of C13 approaches an eclipsed position [16.4 (2)°]. The strain inherent in these fused ring systems is shown by some large angular deviations from ideal geometry. Most notable are the widening of the C2—C3—C7 angles [to 135.2 (2) and 120.43 (15)° in (IIIa) and (IV), respectively], and of the C4—C5—C6 angle to 118.35 (15)° in (IV) and the C5—C4—C9 angle to 122.85 (18)° in (IIIa).

Related literature top

For related literature, see: Allen & Kennard (1993); Chen & Chang (1996); Donkervoort et al. (1996); Ford et al. (2000); Karlsson et al. (1973); Kennedy et al. (2000); Kerr et al. (2001); Khan et al. (1985).

Experimental top

The syntheses and spectroscopic characterizations of compounds (IIIa) and (IV) are described in detail by Kerr et al. (2001). Crystals of both compounds were grown by slow recrystallization from petroleum ether/diethyl ether mixtures at room temperature.

Refinement top

All H atoms were treated as riding, with C—H = 0.93–1.00 Å. For compound (IV), the Freidel equivalents were merged prior to the final refinement.

Computing details top

Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1988) for (IIIa); DENZO (Otwinowski & Minor, 1997) and COLLECT (Nonius, 1998) for (IV). Cell refinement: MSC/AFC Diffractometer Control Software for (IIIa); DENZO and COLLECT for (IV). Data reduction: TEXSAN (Molecular Structure Corporation, 1992) for (IIIa); DENZO and COLLECT for (IV). Program(s) used to solve structure: SIR92 (Altomare et al., 1994) for (IIIa); SHELXS97 (Sheldrick, 1990) for (IV). For both compounds, program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.

Figures top
[Figure 1] Fig. 1. The molecular structure of (IIIa) with 50% probability displacement ellipsoids and H atoms drawn as small spheres of arbitrary size.
[Figure 2] Fig. 2. The molecular structure of (IV) with 50% probability displacement ellipsoids and H atoms drawn as small spheres of arbitrary size.
(IIIa) (3β,3aβ,7β)-(±)-6,6-ethylenedioxy-3,8,8-trimethyl-2,3,3a,4,5,6,7,8- octahydro-3a,7-methanoazulen-2-one top
Crystal data top
C16H22O3F(000) = 568
Mr = 262.34Dx = 1.248 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71069 Å
a = 6.0402 (13) ÅCell parameters from 21 reflections
b = 31.423 (4) Åθ = 7.1–10.7°
c = 7.7111 (13) ŵ = 0.09 mm1
β = 107.469 (15)°T = 295 K
V = 1396.1 (4) Å3Tabular, colourless
Z = 40.50 × 0.40 × 0.15 mm
Data collection top
Rigaku AFC-7S
diffractometer
Rint = 0.061
Radiation source: fine-focus sealed tubeθmax = 26.0°, θmin = 2.6°
Graphite monochromatorh = 07
ω/2θ scansk = 038
2977 measured reflectionsl = 99
2721 independent reflections3 standard reflections every 150 reflections
1522 reflections with I > 2σ(I) intensity decay: 3.0%
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.048H-atom parameters constrained
wR(F2) = 0.142 w = 1/[σ2(Fo2) + (0.0533P)2 + 0.1589P]
where P = (Fo2 + 2Fc2)/3
S = 1.01(Δ/σ)max < 0.001
2721 reflectionsΔρmax = 0.18 e Å3
176 parametersΔρmin = 0.15 e Å3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.017 (2)
Crystal data top
C16H22O3V = 1396.1 (4) Å3
Mr = 262.34Z = 4
Monoclinic, P21/nMo Kα radiation
a = 6.0402 (13) ŵ = 0.09 mm1
b = 31.423 (4) ÅT = 295 K
c = 7.7111 (13) Å0.50 × 0.40 × 0.15 mm
β = 107.469 (15)°
Data collection top
Rigaku AFC-7S
diffractometer
Rint = 0.061
2977 measured reflections3 standard reflections every 150 reflections
2721 independent reflections intensity decay: 3.0%
1522 reflections with I > 2σ(I)
Refinement top
R[F2 > 2σ(F2)] = 0.0480 restraints
wR(F2) = 0.142H-atom parameters constrained
S = 1.01Δρmax = 0.18 e Å3
2721 reflectionsΔρmin = 0.15 e Å3
176 parameters
Special details top

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
O10.4059 (3)0.01602 (5)0.7178 (2)0.0581 (5)
O20.2944 (4)0.21646 (5)0.7625 (3)0.0761 (6)
O30.1227 (4)0.19061 (6)0.9653 (3)0.0815 (7)
C10.3382 (4)0.02062 (7)0.7164 (3)0.0398 (5)
C20.3508 (4)0.05474 (7)0.5890 (3)0.0413 (5)
H20.41170.05210.49210.050*
C30.2608 (3)0.08994 (6)0.6353 (3)0.0334 (5)
C40.2031 (4)0.08565 (6)0.8116 (3)0.0338 (5)
C50.2010 (4)0.03721 (6)0.8395 (3)0.0373 (5)
H50.28070.03000.96650.045*
C60.0401 (4)0.01703 (7)0.7789 (4)0.0539 (7)
H6A0.11560.02410.65400.081*
H6B0.13030.02760.85300.081*
H6C0.02580.01330.79170.081*
C70.1624 (4)0.13113 (7)0.5391 (3)0.0422 (6)
C80.0592 (4)0.15198 (7)0.6824 (3)0.0452 (6)
H80.07630.16940.62120.054*
C90.0155 (4)0.11313 (7)0.7733 (3)0.0466 (6)
H9A0.04910.12090.88440.056*
H9B0.14930.09900.69180.056*
C100.3924 (4)0.10675 (7)0.9690 (3)0.0453 (6)
H10A0.34170.10681.07710.054*
H10B0.53320.08990.99520.054*
C110.4463 (5)0.15231 (7)0.9267 (3)0.0556 (7)
H11A0.52960.16641.03920.067*
H11B0.54700.15170.84970.067*
C120.2313 (5)0.17780 (7)0.8331 (3)0.0541 (7)
C130.0380 (5)0.11880 (8)0.3683 (3)0.0651 (8)
H13A0.02260.10250.28740.098*
H13B0.11070.14410.30770.098*
H13C0.15020.10210.40370.098*
C140.3359 (5)0.15733 (8)0.4728 (4)0.0634 (8)
H14A0.46440.16550.57500.095*
H14B0.26050.18240.41140.095*
H14C0.39130.14050.39040.095*
C150.1855 (8)0.25013 (10)0.8219 (6)0.1173 (16)
H15A0.09190.26640.71880.141*
H15B0.30030.26900.89950.141*
C160.0364 (8)0.23152 (10)0.9246 (6)0.1047 (13)
H16A0.04940.24761.03460.126*
H16B0.12490.23090.85090.126*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0723 (12)0.0379 (9)0.0643 (12)0.0130 (8)0.0209 (10)0.0006 (8)
O20.1065 (16)0.0297 (9)0.0880 (14)0.0054 (10)0.0232 (12)0.0001 (9)
O30.1281 (19)0.0504 (11)0.0743 (13)0.0276 (12)0.0430 (13)0.0070 (10)
C10.0383 (12)0.0361 (12)0.0404 (12)0.0000 (10)0.0048 (10)0.0029 (9)
C20.0458 (13)0.0441 (13)0.0378 (12)0.0002 (10)0.0183 (11)0.0026 (10)
C30.0332 (11)0.0343 (11)0.0314 (11)0.0045 (9)0.0077 (9)0.0011 (8)
C40.0365 (12)0.0321 (11)0.0322 (11)0.0005 (9)0.0092 (9)0.0002 (9)
C50.0403 (13)0.0347 (11)0.0336 (11)0.0018 (9)0.0063 (10)0.0030 (9)
C60.0526 (16)0.0475 (14)0.0625 (16)0.0104 (12)0.0189 (13)0.0029 (12)
C70.0503 (14)0.0355 (12)0.0387 (12)0.0018 (10)0.0104 (10)0.0037 (9)
C80.0410 (13)0.0379 (12)0.0535 (14)0.0111 (10)0.0090 (11)0.0061 (10)
C90.0421 (13)0.0473 (13)0.0530 (14)0.0069 (11)0.0179 (11)0.0037 (11)
C100.0527 (14)0.0402 (12)0.0371 (12)0.0031 (10)0.0047 (11)0.0053 (9)
C110.0612 (17)0.0396 (13)0.0524 (14)0.0023 (12)0.0034 (12)0.0089 (11)
C120.0733 (18)0.0336 (12)0.0555 (16)0.0061 (12)0.0195 (14)0.0032 (11)
C130.076 (2)0.0574 (16)0.0448 (14)0.0011 (14)0.0082 (14)0.0067 (12)
C140.080 (2)0.0524 (15)0.0622 (17)0.0088 (14)0.0287 (15)0.0100 (13)
C150.181 (5)0.0385 (18)0.131 (4)0.018 (2)0.046 (3)0.001 (2)
C160.144 (4)0.058 (2)0.110 (3)0.041 (2)0.035 (3)0.0116 (19)
Geometric parameters (Å, º) top
O1—C11.221 (2)C8—C121.538 (3)
O2—C151.394 (4)C8—C91.541 (3)
O2—C121.429 (3)C8—H80.980
O3—C161.387 (3)C9—H9A0.970
O3—C121.426 (3)C9—H9B0.970
C1—C21.471 (3)C10—C111.525 (3)
C1—C51.527 (3)C10—H10A0.970
C2—C31.328 (3)C10—H10B0.970
C2—H20.930C11—C121.512 (3)
C3—C41.508 (3)C11—H11A0.970
C3—C71.521 (3)C11—H11B0.970
C4—C91.531 (3)C13—H13A0.960
C4—C51.538 (3)C13—H13B0.960
C4—C101.545 (3)C13—H13C0.960
C5—C61.527 (3)C14—H14A0.960
C5—H50.980C14—H14B0.960
C6—H6A0.960C14—H14C0.960
C6—H6B0.960C15—C161.486 (6)
C6—H6C0.960C15—H15A0.970
C7—C141.536 (3)C15—H15B0.970
C7—C131.547 (3)C16—H16A0.970
C7—C81.566 (3)C16—H16B0.970
C15—O2—C12108.3 (3)C8—C9—H9B112
C16—O3—C12108.8 (2)H9A—C9—H9B109.4
O1—C1—C2127.5 (2)C11—C10—C4112.96 (18)
O1—C1—C5124.0 (2)C11—C10—H10A109
C2—C1—C5108.22 (18)C4—C10—H10A109
C3—C2—C1108.7 (2)C11—C10—H10B109
C3—C2—H2126C4—C10—H10B109
C1—C2—H2126H10A—C10—H10B107.8
C2—C3—C4113.09 (18)C12—C11—C10113.0 (2)
C2—C3—C7135.2 (2)C12—C11—H11A109
C4—C3—C7110.71 (17)C10—C11—H11A109
C3—C4—C9101.24 (17)C12—C11—H11B109
C3—C4—C5103.21 (16)C10—C11—H11B109
C9—C4—C5122.85 (18)H11A—C11—H11B108
C3—C4—C10110.70 (18)O3—C12—O2105.36 (19)
C9—C4—C10107.54 (18)O3—C12—C11108.7 (2)
C5—C4—C10110.52 (16)O2—C12—C11110.1 (2)
C6—C5—C1108.28 (17)O3—C12—C8109.7 (2)
C6—C5—C4114.56 (18)O2—C12—C8110.98 (19)
C1—C5—C4102.83 (16)C11—C12—C8111.72 (18)
C6—C5—H5110C7—C13—H13A110
C1—C5—H5110C7—C13—H13B110
C4—C5—H5110H13A—C13—H13B110
C5—C6—H6A110C7—C13—H13C110
C5—C6—H6B110H13A—C13—H13C110
H6A—C6—H6B110H13B—C13—H13C110
C5—C6—H6C110C7—C14—H14A110
H6A—C6—H6C110C7—C14—H14B110
H6B—C6—H6C110H14A—C14—H14B110
C3—C7—C14114.4 (2)C7—C14—H14C110
C3—C7—C13107.07 (17)H14A—C14—H14C110
C14—C7—C13106.8 (2)H14B—C14—H14C110
C3—C7—C8101.06 (16)O2—C15—C16107.3 (3)
C14—C7—C8117.81 (19)O2—C15—H15A110
C13—C7—C8109.3 (2)C16—C15—H15A110
C12—C8—C9107.34 (19)O2—C15—H15B110
C12—C8—C7115.6 (2)C16—C15—H15B110
C9—C8—C7102.85 (17)H15A—C15—H15B108.5
C12—C8—H8110O3—C16—C15103.8 (3)
C9—C8—H8110O3—C16—H16A111
C7—C8—H8110C15—C16—H16A111
C4—C9—C8100.46 (18)O3—C16—H16B111
C4—C9—H9A112C15—C16—H16B111
C8—C9—H9A112H16A—C16—H16B109
C4—C9—H9B112
O1—C1—C2—C3179.2 (2)C14—C7—C8—C9157.1 (2)
C5—C1—C2—C36.5 (2)C13—C7—C8—C980.9 (2)
C1—C2—C3—C47.0 (3)C3—C4—C9—C843.9 (2)
C1—C2—C3—C7160.0 (2)C5—C4—C9—C8157.83 (18)
C2—C3—C4—C9145.19 (19)C10—C4—C9—C872.2 (2)
C7—C3—C4—C925.0 (2)C12—C8—C9—C474.5 (2)
C2—C3—C4—C517.3 (2)C7—C8—C9—C447.9 (2)
C7—C3—C4—C5152.94 (16)C3—C4—C10—C1151.4 (3)
C2—C3—C4—C10101.0 (2)C9—C4—C10—C1158.3 (3)
C7—C3—C4—C1088.8 (2)C5—C4—C10—C11165.16 (19)
O1—C1—C5—C669.3 (3)C4—C10—C11—C1242.2 (3)
C2—C1—C5—C6105.2 (2)C16—O3—C12—O224.0 (3)
O1—C1—C5—C4169.1 (2)C16—O3—C12—C11141.9 (3)
C2—C1—C5—C416.5 (2)C16—O3—C12—C895.6 (3)
C3—C4—C5—C698.0 (2)C15—O2—C12—O311.8 (3)
C9—C4—C5—C614.9 (3)C15—O2—C12—C11128.9 (3)
C10—C4—C5—C6143.6 (2)C15—O2—C12—C8106.9 (3)
C3—C4—C5—C119.22 (19)C10—C11—C12—O377.6 (3)
C9—C4—C5—C1132.2 (2)C10—C11—C12—O2167.5 (2)
C10—C4—C5—C199.2 (2)C10—C11—C12—C843.7 (3)
C2—C3—C7—C1461.0 (3)C9—C8—C12—O359.0 (2)
C4—C3—C7—C14131.8 (2)C7—C8—C12—O3173.09 (17)
C2—C3—C7—C1357.0 (3)C9—C8—C12—O2175.06 (19)
C4—C3—C7—C13110.2 (2)C7—C8—C12—O270.9 (2)
C2—C3—C7—C8171.3 (2)C9—C8—C12—C1161.7 (3)
C4—C3—C7—C84.2 (2)C7—C8—C12—C1152.4 (3)
C3—C7—C8—C1284.9 (2)C12—O2—C15—C163.5 (4)
C14—C7—C8—C1240.5 (3)C12—O3—C16—C1525.6 (4)
C13—C7—C8—C12162.46 (19)O2—C15—C16—O317.9 (4)
C3—C7—C8—C931.8 (2)
(IV) (3β,3aβ,7β,8aα)-(±)-6,6-ethylenedioxy-3,8,8-trimethyl- 1,2,3,3a,4,5,6,7,8,8a-decahydro-3a,7-methanoazulen-2-one top
Crystal data top
C16H24O3F(000) = 288
Mr = 264.35Dx = 1.284 Mg m3
Monoclinic, P21Mo Kα radiation, λ = 0.71073 Å
a = 8.3280 (3) ÅCell parameters from 17654 reflections
b = 8.3930 (3) Åθ = 1.0–27.5°
c = 10.2120 (4) ŵ = 0.09 mm1
β = 106.696 (2)°T = 150 K
V = 683.70 (4) Å3Cut fragment, colourless
Z = 20.50 × 0.35 × 0.10 mm
Data collection top
Nonius KappaCCD area-detector
diffractometer
1579 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.030
Graphite monochromatorθmax = 27.5°, θmin = 3.5°
ϕ + ω scans to fill Ewald sphereh = 1010
5455 measured reflectionsk = 1010
1667 independent reflectionsl = 1313
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)] = 0.031Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.080H-atom parameters constrained
S = 1.07 w = 1/[σ2(Fo2) + (0.0438P)2 + 0.1142P]
where P = (Fo2 + 2Fc2)/3
1667 reflections(Δ/σ)max < 0.001
175 parametersΔρmax = 0.19 e Å3
1 restraintΔρmin = 0.17 e Å3
Crystal data top
C16H24O3V = 683.70 (4) Å3
Mr = 264.35Z = 2
Monoclinic, P21Mo Kα radiation
a = 8.3280 (3) ŵ = 0.09 mm1
b = 8.3930 (3) ÅT = 150 K
c = 10.2120 (4) Å0.50 × 0.35 × 0.10 mm
β = 106.696 (2)°
Data collection top
Nonius KappaCCD area-detector
diffractometer
1579 reflections with I > 2σ(I)
5455 measured reflectionsRint = 0.030
1667 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0311 restraint
wR(F2) = 0.080H-atom parameters constrained
S = 1.07Δρmax = 0.19 e Å3
1667 reflectionsΔρmin = 0.17 e Å3
175 parameters
Special details top

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
O10.48780 (17)0.38785 (19)0.53438 (12)0.0344 (3)
O20.39000 (14)0.31606 (19)0.09467 (12)0.0284 (3)
O30.23261 (14)0.38265 (16)0.04680 (11)0.0213 (3)
C10.3698 (2)0.3367 (2)0.44531 (16)0.0228 (4)
C20.2414 (2)0.2175 (2)0.46290 (17)0.0251 (4)
H2A0.26960.10840.43990.030*
H2B0.23340.21840.55780.030*
C30.07774 (19)0.2755 (2)0.36180 (15)0.0178 (3)
H30.02570.35480.41040.021*
C40.12928 (19)0.3659 (2)0.24538 (15)0.0162 (3)
C50.32299 (19)0.3867 (2)0.29559 (16)0.0196 (3)
H50.37180.30530.24660.024*
C60.3965 (2)0.5464 (3)0.27365 (18)0.0280 (4)
H6A0.35910.62840.32670.042*
H6B0.51910.54000.30370.042*
H6C0.35870.57410.17640.042*
C70.0616 (2)0.1534 (2)0.28849 (16)0.0203 (3)
C80.1065 (2)0.2061 (2)0.13533 (16)0.0182 (3)
H80.15200.11380.07400.022*
C90.06617 (19)0.2550 (2)0.12185 (15)0.0173 (3)
H9A0.05590.31180.03490.021*
H9B0.14060.16160.12820.021*
C100.0321 (2)0.5234 (2)0.21179 (16)0.0194 (3)
H10A0.05530.57290.13110.023*
H10B0.07130.59760.28990.023*
C110.1575 (2)0.4974 (2)0.18208 (17)0.0219 (4)
H11A0.21700.59300.13550.026*
H11B0.18450.48550.26990.026*
C120.22193 (19)0.3511 (2)0.09335 (15)0.0189 (3)
C130.0031 (3)0.0192 (2)0.2963 (2)0.0288 (4)
H13A0.04220.05270.39220.043*
H13B0.08780.08950.24630.043*
H13C0.09600.02510.25550.043*
C140.2077 (2)0.1542 (3)0.35251 (18)0.0290 (4)
H14A0.29680.08350.30020.044*
H14B0.16780.11670.44730.044*
H14C0.25150.26270.35090.044*
C150.5019 (2)0.3494 (3)0.03634 (17)0.0279 (4)
H15A0.54470.24960.08570.034*
H15B0.59810.41390.02820.034*
C160.3975 (2)0.4416 (2)0.10943 (17)0.0241 (4)
H16A0.40430.55770.09460.029*
H16B0.43350.41930.20880.029*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0298 (7)0.0395 (8)0.0240 (6)0.0062 (6)0.0083 (5)0.0033 (6)
O20.0147 (5)0.0452 (9)0.0235 (6)0.0015 (6)0.0028 (4)0.0075 (6)
O30.0173 (5)0.0290 (7)0.0153 (5)0.0005 (5)0.0008 (4)0.0031 (5)
C10.0195 (8)0.0238 (9)0.0216 (8)0.0059 (7)0.0002 (6)0.0012 (7)
C20.0230 (8)0.0283 (9)0.0199 (8)0.0015 (7)0.0003 (6)0.0072 (7)
C30.0181 (7)0.0203 (8)0.0145 (7)0.0012 (6)0.0040 (6)0.0012 (6)
C40.0160 (7)0.0172 (8)0.0143 (6)0.0001 (6)0.0025 (5)0.0003 (6)
C50.0159 (7)0.0230 (8)0.0181 (7)0.0009 (7)0.0020 (6)0.0008 (6)
C60.0212 (8)0.0338 (11)0.0251 (8)0.0082 (8)0.0006 (7)0.0033 (8)
C70.0195 (8)0.0232 (9)0.0172 (8)0.0013 (7)0.0039 (6)0.0029 (7)
C80.0196 (7)0.0190 (8)0.0153 (7)0.0027 (6)0.0038 (6)0.0004 (6)
C90.0176 (7)0.0180 (8)0.0154 (7)0.0010 (6)0.0035 (5)0.0012 (6)
C100.0214 (8)0.0166 (8)0.0181 (7)0.0026 (7)0.0023 (6)0.0001 (6)
C110.0190 (8)0.0234 (9)0.0214 (8)0.0053 (7)0.0030 (6)0.0011 (7)
C120.0143 (7)0.0260 (9)0.0156 (7)0.0002 (7)0.0032 (5)0.0023 (7)
C130.0337 (10)0.0208 (9)0.0294 (9)0.0028 (8)0.0052 (7)0.0049 (7)
C140.0244 (9)0.0423 (12)0.0212 (8)0.0052 (8)0.0077 (7)0.0069 (8)
C150.0170 (7)0.0385 (11)0.0241 (8)0.0002 (8)0.0009 (6)0.0013 (8)
C160.0197 (8)0.0268 (9)0.0211 (8)0.0026 (7)0.0016 (6)0.0030 (7)
Geometric parameters (Å, º) top
O1—C11.210 (2)C7—C81.564 (2)
O2—C151.421 (2)C8—C121.533 (2)
O2—C121.4341 (19)C8—C91.539 (2)
O3—C161.427 (2)C8—H81.000
O3—C121.4329 (17)C9—H9A0.990
C1—C21.513 (3)C9—H9B0.990
C1—C51.524 (2)C10—C111.536 (2)
C2—C31.533 (2)C10—H10A0.990
C2—H2A0.990C10—H10B0.990
C2—H2B0.990C11—C121.529 (2)
C3—C71.568 (2)C11—H11A0.990
C3—C41.571 (2)C11—H11B0.990
C3—H31.000C13—H13A0.980
C4—C91.534 (2)C13—H13B0.980
C4—C101.536 (2)C13—H13C0.980
C4—C51.556 (2)C14—H14A0.980
C5—C61.517 (3)C14—H14B0.980
C5—H51.000C14—H14C0.980
C6—H6A0.980C15—C161.511 (3)
C6—H6B0.980C15—H15A0.990
C6—H6C0.980C15—H15B0.990
C7—C141.538 (2)C16—H16A0.990
C7—C131.539 (3)C16—H16B0.990
C15—O2—C12109.17 (12)C4—C9—H9A112
C16—O3—C12106.70 (12)C8—C9—H9A112
O1—C1—C2126.49 (16)C4—C9—H9B112
O1—C1—C5125.11 (17)C8—C9—H9B112
C2—C1—C5108.38 (13)H9A—C9—H9B109
C1—C2—C3103.41 (14)C11—C10—C4111.55 (14)
C1—C2—H2A111C11—C10—H10A109
C3—C2—H2A111C4—C10—H10A109
C1—C2—H2B111C11—C10—H10B109
C3—C2—H2B111C4—C10—H10B109
H2A—C2—H2B109H10A—C10—H10B108
C2—C3—C7120.43 (15)C12—C11—C10113.40 (13)
C2—C3—C4106.24 (13)C12—C11—H11A109
C7—C3—C4106.27 (12)C10—C11—H11A109
C2—C3—H3108C12—C11—H11B109
C7—C3—H3108C10—C11—H11B109
C4—C3—H3108H11A—C11—H11B108
C9—C4—C10107.72 (12)O3—C12—O2105.46 (12)
C9—C4—C5114.65 (13)O3—C12—C11110.74 (14)
C10—C4—C5113.99 (14)O2—C12—C11109.65 (13)
C9—C4—C3103.05 (13)O3—C12—C8106.26 (12)
C10—C4—C3110.11 (13)O2—C12—C8111.70 (14)
C5—C4—C3106.73 (12)C11—C12—C8112.74 (13)
C6—C5—C1113.18 (14)C7—C13—H13A110
C6—C5—C4118.35 (15)C7—C13—H13B110
C1—C5—C4104.00 (12)H13A—C13—H13B110
C6—C5—H5107C7—C13—H13C110
C1—C5—H5107H13A—C13—H13C110
C4—C5—H5107H13B—C13—H13C110
C5—C6—H6A110C7—C14—H14A110
C5—C6—H6B110C7—C14—H14B110
H6A—C6—H6B110H14A—C14—H14B110
C5—C6—H6C110C7—C14—H14C110
H6A—C6—H6C110H14A—C14—H14C110
H6B—C6—H6C110H14B—C14—H14C110
C14—C7—C13106.84 (16)O2—C15—C16104.55 (13)
C14—C7—C8115.64 (14)O2—C15—H15A111
C13—C7—C8107.35 (15)C16—C15—H15A111
C14—C7—C3111.19 (15)O2—C15—H15B111
C13—C7—C3112.97 (14)C16—C15—H15B111
C8—C7—C3102.94 (13)H15A—C15—H15B109
C12—C8—C9106.87 (13)O3—C16—C15102.54 (13)
C12—C8—C7117.07 (13)O3—C16—H16A111
C9—C8—C7101.75 (12)C15—C16—H16A111
C12—C8—H8110O3—C16—H16B111
C9—C8—H8110C15—C16—H16B111
C7—C8—H8110H16A—C16—H16B109
C4—C9—C8101.33 (12)
O1—C1—C2—C3143.48 (19)C13—C7—C8—C982.17 (16)
C5—C1—C2—C334.84 (18)C3—C7—C8—C937.26 (16)
C1—C2—C3—C7147.82 (14)C10—C4—C9—C874.09 (15)
C1—C2—C3—C427.19 (18)C5—C4—C9—C8157.87 (13)
C2—C3—C4—C9110.41 (14)C3—C4—C9—C842.31 (15)
C7—C3—C4—C918.98 (16)C12—C8—C9—C473.32 (14)
C2—C3—C4—C10134.90 (14)C7—C8—C9—C449.96 (16)
C7—C3—C4—C1095.71 (15)C9—C4—C10—C1159.43 (16)
C2—C3—C4—C510.70 (18)C5—C4—C10—C11172.15 (12)
C7—C3—C4—C5140.09 (14)C3—C4—C10—C1152.25 (16)
O1—C1—C5—C620.6 (3)C4—C10—C11—C1242.23 (18)
C2—C1—C5—C6157.73 (15)C16—O3—C12—O227.63 (18)
O1—C1—C5—C4150.35 (18)C16—O3—C12—C1190.91 (16)
C2—C1—C5—C427.99 (18)C16—O3—C12—C8146.34 (13)
C9—C4—C5—C6110.04 (17)C15—O2—C12—O38.7 (2)
C10—C4—C5—C614.8 (2)C15—O2—C12—C11110.60 (16)
C3—C4—C5—C6136.55 (15)C15—O2—C12—C8123.68 (16)
C9—C4—C5—C1123.41 (15)C10—C11—C12—O376.22 (17)
C10—C4—C5—C1111.78 (15)C10—C11—C12—O2167.81 (13)
C3—C4—C5—C19.99 (18)C10—C11—C12—C842.68 (19)
C2—C3—C7—C14103.72 (18)C9—C8—C12—O362.21 (15)
C4—C3—C7—C14135.66 (14)C7—C8—C12—O3175.41 (13)
C2—C3—C7—C1316.4 (2)C9—C8—C12—O2176.73 (12)
C4—C3—C7—C13104.21 (16)C7—C8—C12—O270.07 (18)
C2—C3—C7—C8131.86 (15)C9—C8—C12—C1159.27 (16)
C4—C3—C7—C811.24 (16)C7—C8—C12—C1153.93 (19)
C14—C7—C8—C1242.7 (2)C12—O2—C15—C1612.3 (2)
C13—C7—C8—C12161.78 (14)C12—O3—C16—C1534.46 (18)
C3—C7—C8—C1278.79 (16)O2—C15—C16—O328.40 (19)
C14—C7—C8—C9158.70 (16)

Experimental details

(IIIa)(IV)
Crystal data
Chemical formulaC16H22O3C16H24O3
Mr262.34264.35
Crystal system, space groupMonoclinic, P21/nMonoclinic, P21
Temperature (K)295150
a, b, c (Å)6.0402 (13), 31.423 (4), 7.7111 (13)8.3280 (3), 8.3930 (3), 10.2120 (4)
β (°) 107.469 (15) 106.696 (2)
V3)1396.1 (4)683.70 (4)
Z42
Radiation typeMo KαMo Kα
µ (mm1)0.090.09
Crystal size (mm)0.50 × 0.40 × 0.150.50 × 0.35 × 0.10
Data collection
DiffractometerRigaku AFC-7S
diffractometer
Nonius KappaCCD area-detector
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
2977, 2721, 1522 5455, 1667, 1579
Rint0.0610.030
(sin θ/λ)max1)0.6170.649
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.048, 0.142, 1.01 0.031, 0.080, 1.07
No. of reflections27211667
No. of parameters176175
No. of restraints01
H-atom treatmentH-atom parameters constrainedH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.18, 0.150.19, 0.17

Computer programs: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1988), DENZO (Otwinowski & Minor, 1997) and COLLECT (Nonius, 1998), MSC/AFC Diffractometer Control Software, DENZO and COLLECT, TEXSAN (Molecular Structure Corporation, 1992), SIR92 (Altomare et al., 1994), SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), ORTEPII (Johnson, 1976), SHELXL97.

Selected geometric parameters (Å, º) for (IIIa) top
O1—C11.221 (2)C2—C31.328 (3)
C1—C21.471 (3)C3—C41.508 (3)
C1—C51.527 (3)C3—C71.521 (3)
C2—C1—C5108.22 (18)C9—C4—C5122.85 (18)
C2—C3—C7135.2 (2)C6—C5—C4114.56 (18)
C5—C1—C2—C36.5 (2)C3—C4—C5—C119.22 (19)
C1—C2—C3—C47.0 (3)C4—C3—C7—C84.2 (2)
C7—C3—C4—C925.0 (2)C3—C7—C8—C931.8 (2)
C2—C3—C4—C517.3 (2)C3—C4—C9—C843.9 (2)
C2—C1—C5—C416.5 (2)C7—C8—C9—C447.9 (2)
Selected geometric parameters (Å, º) for (IV) top
O1—C11.210 (2)C3—C71.568 (2)
C1—C21.513 (3)C3—C41.571 (2)
C1—C51.524 (2)C4—C51.556 (2)
C2—C1—C5108.38 (13)C9—C4—C5114.65 (13)
C2—C3—C7120.43 (15)C6—C5—C4118.35 (15)
C5—C1—C2—C334.84 (18)C3—C4—C5—C19.99 (18)
C1—C2—C3—C427.19 (18)C4—C3—C7—C811.24 (16)
C7—C3—C4—C918.98 (16)C3—C7—C8—C937.26 (16)
C2—C3—C4—C510.70 (18)C3—C4—C9—C842.31 (15)
C2—C1—C5—C427.99 (18)C7—C8—C9—C449.96 (16)
 

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