Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536802015957/bt6190sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536802015957/bt61903sup2.hkl |
CCDC reference: 198334
[2](2,5)Furano[2]paracyclophane (1) was treated with bromine in methanol in the presence of potassium acetate to produce the bis-ketal (2), which on hydrolysis with dilute sulfuric acid provided the title compound (3) (Cope & Pawson, 1968; cf. Cram et al., 1966). Single crystals were obtained from ethanol.
Hydrogen atoms were included using a riding model with fixed C—H bond lengths (aromatic 0.95, methylene 0.99 Å); U(H) values were fixed at 1.2 times the U(eq) of the parent atom.
Data collection: P3 (Nicolet, 1987); cell refinement: P3; data reduction: XDISK (Nicolet, 1987); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP (Siemens, 1994); software used to prepare material for publication: SHELXL97.
C14H14O2 | F(000) = 456 |
Mr = 214.25 | Dx = 1.301 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
a = 11.164 (3) Å | Cell parameters from 50 reflections |
b = 7.662 (3) Å | θ = 10–11.5° |
c = 13.063 (4) Å | µ = 0.09 mm−1 |
β = 101.84 (3)° | T = 173 K |
V = 1093.6 (6) Å3 | Prism, colourless |
Z = 4 | 0.52 × 0.42 × 0.40 mm |
Nicolet R3 diffractometer | Rint = 0.025 |
Radiation source: fine-focus sealed tube | θmax = 25.0°, θmin = 3.1° |
Graphite monochromator | h = −13→2 |
ω scans | k = −9→0 |
2335 measured reflections | l = −15→15 |
1913 independent reflections | 3 standard reflections every 147 reflections |
1263 reflections with I > 2σ(I) | intensity decay: none |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.038 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.088 | H-atom parameters constrained |
S = 0.89 | w = 1/[σ2(Fo2) + (0.0483P)2] where P = (Fo2 + 2Fc2)/3 |
1913 reflections | (Δ/σ)max < 0.001 |
145 parameters | Δρmax = 0.19 e Å−3 |
0 restraints | Δρmin = −0.15 e Å−3 |
C14H14O2 | V = 1093.6 (6) Å3 |
Mr = 214.25 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 11.164 (3) Å | µ = 0.09 mm−1 |
b = 7.662 (3) Å | T = 173 K |
c = 13.063 (4) Å | 0.52 × 0.42 × 0.40 mm |
β = 101.84 (3)° |
Nicolet R3 diffractometer | Rint = 0.025 |
2335 measured reflections | 3 standard reflections every 147 reflections |
1913 independent reflections | intensity decay: none |
1263 reflections with I > 2σ(I) |
R[F2 > 2σ(F2)] = 0.038 | 0 restraints |
wR(F2) = 0.088 | H-atom parameters constrained |
S = 0.89 | Δρmax = 0.19 e Å−3 |
1913 reflections | Δρmin = −0.15 e Å−3 |
145 parameters |
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. Non-bonded distances: 2.7996 (0.0025) C3 - C12 2.8335 (0.0025) C6 - C9 Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane) 4.8719 (0.0105) x − 5.5652 (0.0046) y + 5.6196 (0.0139) z = 3.8438 (0.0045) * −0.0021 (0.0009) C10 * 0.0021 (0.0009) C11 * −0.0021 (0.0009) C13 * 0.0021 (0.0009) C14 − 0.1063 (0.0025) C9 − 0.1065 (0.0025) C12 Rms deviation of fitted atoms = 0.0021 |
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. |
x | y | z | Uiso*/Ueq | ||
O1 | 0.42493 (13) | 0.27584 (17) | 0.00371 (10) | 0.0421 (4) | |
O2 | 0.38876 (13) | 0.59815 (15) | 0.33598 (10) | 0.0400 (4) | |
C1 | 0.68151 (18) | 0.1319 (2) | 0.12563 (14) | 0.0343 (5) | |
H1A | 0.6512 | 0.0358 | 0.0765 | 0.041* | |
H1B | 0.7721 | 0.1276 | 0.1420 | 0.041* | |
C2 | 0.63780 (18) | 0.3097 (2) | 0.07459 (15) | 0.0336 (5) | |
H2A | 0.6858 | 0.4053 | 0.1144 | 0.040* | |
H2B | 0.6516 | 0.3128 | 0.0021 | 0.040* | |
C3 | 0.50369 (18) | 0.3361 (2) | 0.07330 (14) | 0.0304 (4) | |
C4 | 0.47128 (17) | 0.4292 (2) | 0.16417 (13) | 0.0281 (4) | |
H4 | 0.5203 | 0.5248 | 0.1942 | 0.034* | |
C5 | 0.37603 (17) | 0.3825 (2) | 0.20429 (13) | 0.0269 (4) | |
H5 | 0.3175 | 0.3039 | 0.1664 | 0.032* | |
C6 | 0.35844 (16) | 0.4502 (2) | 0.30735 (14) | 0.0285 (4) | |
C7 | 0.30701 (17) | 0.3257 (2) | 0.37689 (14) | 0.0325 (5) | |
H7A | 0.2473 | 0.2470 | 0.3329 | 0.039* | |
H7B | 0.2630 | 0.3929 | 0.4224 | 0.039* | |
C8 | 0.40895 (18) | 0.2146 (2) | 0.44610 (14) | 0.0368 (5) | |
H8A | 0.4521 | 0.2859 | 0.5056 | 0.044* | |
H8B | 0.3717 | 0.1132 | 0.4747 | 0.044* | |
C9 | 0.49910 (17) | 0.1518 (2) | 0.38272 (14) | 0.0297 (4) | |
C10 | 0.61017 (17) | 0.2368 (2) | 0.38916 (14) | 0.0308 (4) | |
H10 | 0.6408 | 0.3100 | 0.4473 | 0.037* | |
C11 | 0.67682 (17) | 0.2157 (2) | 0.31122 (14) | 0.0319 (5) | |
H11 | 0.7530 | 0.2741 | 0.3169 | 0.038* | |
C12 | 0.63335 (16) | 0.1098 (2) | 0.22473 (13) | 0.0287 (4) | |
C13 | 0.53257 (17) | 0.0051 (2) | 0.22694 (14) | 0.0308 (5) | |
H13 | 0.5087 | −0.0812 | 0.1745 | 0.037* | |
C14 | 0.46627 (17) | 0.0254 (2) | 0.30531 (15) | 0.0326 (5) | |
H14 | 0.3977 | −0.0477 | 0.3061 | 0.039* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0445 (9) | 0.0480 (8) | 0.0314 (7) | 0.0050 (7) | 0.0020 (7) | −0.0041 (6) |
O2 | 0.0546 (10) | 0.0286 (7) | 0.0380 (8) | −0.0011 (7) | 0.0127 (7) | −0.0029 (6) |
C1 | 0.0331 (11) | 0.0309 (10) | 0.0396 (11) | 0.0064 (9) | 0.0090 (9) | 0.0015 (8) |
C2 | 0.0371 (12) | 0.0323 (10) | 0.0342 (11) | 0.0037 (9) | 0.0137 (9) | 0.0007 (8) |
C3 | 0.0382 (12) | 0.0251 (9) | 0.0277 (10) | 0.0031 (9) | 0.0063 (9) | 0.0068 (8) |
C4 | 0.0349 (11) | 0.0209 (8) | 0.0273 (10) | 0.0041 (8) | 0.0039 (9) | 0.0035 (7) |
C5 | 0.0292 (10) | 0.0246 (8) | 0.0250 (9) | 0.0035 (8) | 0.0013 (8) | 0.0032 (7) |
C6 | 0.0257 (10) | 0.0267 (9) | 0.0308 (10) | 0.0064 (8) | 0.0009 (8) | 0.0011 (8) |
C7 | 0.0338 (11) | 0.0335 (10) | 0.0310 (10) | 0.0010 (9) | 0.0087 (9) | 0.0018 (8) |
C8 | 0.0393 (12) | 0.0401 (10) | 0.0303 (10) | 0.0002 (10) | 0.0060 (9) | 0.0089 (8) |
C9 | 0.0320 (11) | 0.0265 (9) | 0.0277 (10) | 0.0024 (8) | −0.0001 (8) | 0.0101 (7) |
C10 | 0.0311 (11) | 0.0295 (9) | 0.0278 (10) | −0.0030 (9) | −0.0036 (8) | 0.0024 (8) |
C11 | 0.0257 (10) | 0.0279 (9) | 0.0390 (11) | 0.0009 (9) | −0.0003 (9) | 0.0041 (8) |
C12 | 0.0273 (11) | 0.0207 (9) | 0.0359 (11) | 0.0067 (8) | 0.0014 (8) | 0.0030 (8) |
C13 | 0.0329 (11) | 0.0195 (8) | 0.0369 (11) | 0.0028 (8) | 0.0001 (9) | −0.0002 (7) |
C14 | 0.0286 (11) | 0.0234 (9) | 0.0428 (11) | −0.0016 (8) | 0.0008 (9) | 0.0099 (8) |
O1—C3 | 1.218 (2) | C7—H7A | 0.9900 |
O2—C6 | 1.219 (2) | C7—H7B | 0.9900 |
C1—C12 | 1.510 (2) | C8—C9 | 1.507 (2) |
C1—C2 | 1.551 (2) | C8—H8A | 0.9900 |
C1—H1A | 0.9900 | C8—H8B | 0.9900 |
C1—H1B | 0.9900 | C9—C10 | 1.388 (2) |
C2—C3 | 1.507 (3) | C9—C14 | 1.394 (2) |
C2—H2A | 0.9900 | C10—C11 | 1.388 (3) |
C2—H2B | 0.9900 | C10—H10 | 0.9500 |
C3—C4 | 1.492 (2) | C11—C12 | 1.395 (2) |
C4—C5 | 1.327 (2) | C11—H11 | 0.9500 |
C4—H4 | 0.9500 | C12—C13 | 1.387 (2) |
C5—C6 | 1.493 (2) | C13—C14 | 1.390 (3) |
C5—H5 | 0.9500 | C13—H13 | 0.9500 |
C6—C7 | 1.510 (2) | C14—H14 | 0.9500 |
C7—C8 | 1.554 (3) | ||
C12—C1—C2 | 109.33 (14) | C6—C7—H7B | 109.2 |
C12—C1—H1A | 109.8 | C8—C7—H7B | 109.2 |
C2—C1—H1A | 109.8 | H7A—C7—H7B | 107.9 |
C12—C1—H1B | 109.8 | C9—C8—C7 | 110.32 (15) |
C2—C1—H1B | 109.8 | C9—C8—H8A | 109.6 |
H1A—C1—H1B | 108.3 | C7—C8—H8A | 109.6 |
C3—C2—C1 | 110.29 (15) | C9—C8—H8B | 109.6 |
C3—C2—H2A | 109.6 | C7—C8—H8B | 109.6 |
C1—C2—H2A | 109.6 | H8A—C8—H8B | 108.1 |
C3—C2—H2B | 109.6 | C10—C9—C14 | 117.95 (18) |
C1—C2—H2B | 109.6 | C10—C9—C8 | 120.38 (16) |
H2A—C2—H2B | 108.1 | C14—C9—C8 | 120.98 (17) |
O1—C3—C4 | 121.27 (18) | C9—C10—C11 | 120.50 (17) |
O1—C3—C2 | 121.37 (17) | C9—C10—H10 | 119.7 |
C4—C3—C2 | 117.25 (17) | C11—C10—H10 | 119.7 |
C5—C4—C3 | 122.02 (17) | C10—C11—C12 | 120.80 (17) |
C5—C4—H4 | 119.0 | C10—C11—H11 | 119.6 |
C3—C4—H4 | 119.0 | C12—C11—H11 | 119.6 |
C4—C5—C6 | 121.78 (17) | C13—C12—C11 | 117.95 (17) |
C4—C5—H5 | 119.1 | C13—C12—C1 | 121.04 (16) |
C6—C5—H5 | 119.1 | C11—C12—C1 | 120.24 (17) |
O2—C6—C5 | 121.33 (16) | C12—C13—C14 | 120.48 (17) |
O2—C6—C7 | 121.25 (16) | C12—C13—H13 | 119.8 |
C5—C6—C7 | 117.36 (15) | C14—C13—H13 | 119.8 |
C6—C7—C8 | 111.87 (15) | C13—C14—C9 | 120.80 (17) |
C6—C7—H7A | 109.2 | C13—C14—H14 | 119.6 |
C8—C7—H7A | 109.2 | C9—C14—H14 | 119.6 |
C12—C1—C2—C3 | −45.7 (2) | C14—C9—C10—C11 | 9.7 (3) |
C1—C2—C3—O1 | −84.5 (2) | C8—C9—C10—C11 | −160.82 (16) |
C1—C2—C3—C4 | 91.75 (18) | C9—C10—C11—C12 | 0.4 (3) |
O1—C3—C4—C5 | 34.6 (3) | C10—C11—C12—C13 | −10.2 (3) |
C2—C3—C4—C5 | −141.63 (17) | C10—C11—C12—C1 | 159.87 (16) |
C3—C4—C5—C6 | 167.20 (15) | C2—C1—C12—C13 | 101.53 (19) |
C4—C5—C6—O2 | 34.6 (3) | C2—C1—C12—C11 | −68.2 (2) |
C4—C5—C6—C7 | −142.65 (17) | C11—C12—C13—C14 | 9.7 (2) |
O2—C6—C7—C8 | −91.0 (2) | C1—C12—C13—C14 | −160.22 (16) |
C5—C6—C7—C8 | 86.32 (19) | C12—C13—C14—C9 | 0.4 (3) |
C6—C7—C8—C9 | −42.9 (2) | C10—C9—C14—C13 | −10.1 (2) |
C7—C8—C9—C10 | 100.1 (2) | C8—C9—C14—C13 | 160.34 (16) |
C7—C8—C9—C14 | −70.2 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
C1—H1A···O1i | 0.99 | 2.67 | 3.633 (3) | 163 |
C7—H7A···O2ii | 0.99 | 2.66 | 3.613 (3) | 161 |
C8—H8A···O2iii | 0.99 | 2.59 | 3.553 (3) | 164 |
Symmetry codes: (i) −x+1, −y, −z; (ii) −x+1/2, y−1/2, −z+1/2; (iii) −x+1, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C14H14O2 |
Mr | 214.25 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 173 |
a, b, c (Å) | 11.164 (3), 7.662 (3), 13.063 (4) |
β (°) | 101.84 (3) |
V (Å3) | 1093.6 (6) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.52 × 0.42 × 0.40 |
Data collection | |
Diffractometer | Nicolet R3 diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2335, 1913, 1263 |
Rint | 0.025 |
(sin θ/λ)max (Å−1) | 0.594 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.038, 0.088, 0.89 |
No. of reflections | 1913 |
No. of parameters | 145 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.19, −0.15 |
Computer programs: P3 (Nicolet, 1987), P3, XDISK (Nicolet, 1987), SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), XP (Siemens, 1994), SHELXL97.
C1—C2 | 1.551 (2) | C7—C8 | 1.554 (3) |
C4—C5 | 1.327 (2) | ||
C12—C1—C2 | 109.33 (14) | C10—C9—C14 | 117.95 (18) |
C9—C8—C7 | 110.32 (15) | C13—C12—C11 | 117.95 (17) |
C12—C1—C2—C3 | −45.7 (2) | C5—C6—C7—C8 | 86.32 (19) |
C1—C2—C3—C4 | 91.75 (18) | C6—C7—C8—C9 | −42.9 (2) |
C2—C3—C4—C5 | −141.63 (17) | C7—C8—C9—C10 | 100.1 (2) |
C3—C4—C5—C6 | 167.20 (15) | C2—C1—C12—C13 | 101.53 (19) |
C4—C5—C6—C7 | −142.65 (17) |
D—H···A | D—H | H···A | D···A | D—H···A |
C1—H1A···O1i | 0.99 | 2.67 | 3.633 (3) | 163.1 |
C7—H7A···O2ii | 0.99 | 2.66 | 3.613 (3) | 160.5 |
C8—H8A···O2iii | 0.99 | 2.59 | 3.553 (3) | 163.5 |
Symmetry codes: (i) −x+1, −y, −z; (ii) −x+1/2, y−1/2, −z+1/2; (iii) −x+1, −y+1, −z+1. |
The title enedione (3) is useful as a starting material in cyclophane chemistry. Having investigated its chemical behaviour and spectroscopic data (Noble et al., 1984a,b), we now describe its crystal structure.
The molecule of (3) (Fig. 1) possesses approximate twofold symmetry, as can be seen from the torsion angles in Table 1. Of the usual features of strained cyclophanes (see e.g. Jones et al., 2002), it shows a flattened boat shape for the six-membered ring (atoms C9 and C12 both lie 0.106 (3) Å out of the plane of C10,C11,C13,C14), with narrow ring angles at C9 and C12. However, bond lengths and angles in the bridges C1—C2 and C7—C8 are normal for sp3 carbons. Contacts involving the bridgehead atoms are C3···C12 2.800 (3) and C6···C9 2.834 (3) Å.
The double bond C4═C5 is significantly twisted, with a torsion angle C3—C4—C5—C6 of 167.20 (15)°.
The crystal packing involves three H···O contacts that could be considered as hydrogen bonds (Table 2). These connect the molecules in a three-dimensional network, a section of which is shown in Fig. 2. The hydrogen bond C1—H1···O1 forms rings of graph set R22(10) in the regions z ~0,1, ··· and C8—H8A···O2 rings of the same set in the regions z ~1/2, 3/2, ···; the two hydrogen bonds for which O2 is the acceptor combine to form larger rings R46(18). There are no short contacts of the form C—H···Cg, where Cg is the ring centroid of C10,C11,C13,C14 (Jones et al., 2002); the shortest such contact is H2a···Cg 3.11 Å (C—H normalized to 1.08 Å).