Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270102005140/bm1493sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270102005140/bm1493IVasup2.hkl | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270102005140/bm1493IVbsup3.hkl | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270102005140/bm1493IVdsup4.hkl |
CCDC references: 187941; 187942; 187943
To a solution of 1,2,4,5-hexatetraene (Hopf et al., 1978), (I) (18.8 g, 0.24 mol), in diethyl ether was added methyl propiolate, (II) (16.8 g, 0.2 mol), in toluene (200 ml). The mixture was heated to 330 K for several hours while most of the ether distilled off. To complete the cycloaddition, the reaction mixture was kept at 353 K for 1 d. For work-up, the solvent was removed in vacuo and the oily residue taken up in dichloromethane/ethyl acetate (8:2) and passed through a silica gel column. The prepurified product mixture (16.2 g, 25% yield) was fractionated by middle-pressure Is this medium-pressure? chromatography using dichloromethane/ethyl acetate (98:2, v/v) as eluent. The first fraction consisted of (IVd) (4.02 g, 6.2%), the second of (IVc) (5.19 g, 8.0%), the third of (IVa) (4.15 g, 6.4%) and the fourth of (IVb) (2.6 g, 4%). Analytically pure samples were obtained by recrystallization from chloroform. Spectroscopic and analytical data, including the separation of chiral derivatives by high-pressure liquid chromatography on optically active columns, are described by Hillmer (1991). Single crystals were obtained by evaporation from chloroform/cyclohexane for (IVa), or diffusion of cyclohexane into a chloroform solution for (IVb) and (IVd).
Methyl H atoms were identified in difference syntheses, idealized and then refined using rigid methyl groups allowed to rotate but not tip. Other H atoms were included using a riding model. C—H bond lengths were fixed as follows: CH 0.95 Å, CH2 0.98 Å and CH3 0.99 Å. Uiso(H) values were fixed at 1.2Ueq for the parent atom. For compound (IVb), Friedel-opposite reflections were merged because the anomalous differences were not significant and the absolute structure could therefore not be determined.
For all compounds, data collection: P3 Software (Nicolet, 1987); cell refinement: P3 Software; 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.
C20H20O4 | F(000) = 688 |
Mr = 324.36 | Dx = 1.353 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
a = 8.096 (4) Å | Cell parameters from 46 reflections |
b = 21.282 (11) Å | θ = 10–12° |
c = 9.281 (5) Å | µ = 0.09 mm−1 |
β = 95.28 (4)° | T = 178 K |
V = 1592.3 (14) Å3 | Irregular, colourless |
Z = 4 | 0.7 × 0.6 × 0.5 mm |
Nicolet R3 diffractometer | Rint = 0.010 |
Radiation source: fine-focus sealed tube | θmax = 25.0°, θmin = 3.5° |
Graphite monochromator | h = −9→9 |
ω scans | k = −25→0 |
2954 measured reflections | l = −11→1 |
2767 independent reflections | 3 standard reflections every 147 reflections |
2296 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)] = 0.041 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.119 | H-atom parameters constrained |
S = 1.05 | w = 1/[σ2(Fo2) + (0.064P)2 + 0.628P] where P = (Fo2 + 2Fc2)/3 |
2767 reflections | (Δ/σ)max = 0.001 |
219 parameters | Δρmax = 0.23 e Å−3 |
0 restraints | Δρmin = −0.20 e Å−3 |
C20H20O4 | V = 1592.3 (14) Å3 |
Mr = 324.36 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 8.096 (4) Å | µ = 0.09 mm−1 |
b = 21.282 (11) Å | T = 178 K |
c = 9.281 (5) Å | 0.7 × 0.6 × 0.5 mm |
β = 95.28 (4)° |
Nicolet R3 diffractometer | Rint = 0.010 |
2954 measured reflections | 3 standard reflections every 147 reflections |
2767 independent reflections | intensity decay: none |
2296 reflections with I > 2σ(I) |
R[F2 > 2σ(F2)] = 0.041 | 0 restraints |
wR(F2) = 0.119 | H-atom parameters constrained |
S = 1.05 | Δρmax = 0.23 e Å−3 |
2767 reflections | Δρmin = −0.20 e Å−3 |
219 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 distance: 4.1091 (0.0027) C17 - C19 Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane) 6.1606 (0.0055) x + 13.6573 (0.0141) y + 0.2337 (0.0105) z = 11.5304 (0.0125) * 0.0017 (0.0008) C4 * -0.0017 (0.0008) C5 * 0.0017 (0.0008) C7 * -0.0017 (0.0008) C8 - 0.1574 (0.0023) C3 - 0.1561 (0.0023) C6 Rms deviation of fitted atoms = 0.0017 6.1131 (0.0055) x + 13.8004 (0.0139) y + 0.2496 (0.0101) z = 8.5486 (0.0112) Angle to previous plane (with approximate e.s.d.) = 0.52 (0.10) * -0.0032 (0.0007) C12 * 0.0032 (0.0008) C13 * -0.0031 (0.0007) C15 * 0.0031 (0.0007) C16 0.1649 (0.0023) C11 0.1610 (0.0023) C14 Rms deviation of fitted atoms = 0.0032 |
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 | ||
C1 | 0.0866 (2) | 0.62940 (8) | 0.40719 (18) | 0.0358 (4) | |
H1A | −0.0063 | 0.6368 | 0.3321 | 0.043* | |
H1B | 0.1521 | 0.5934 | 0.3757 | 0.043* | |
C2 | 0.2011 (2) | 0.69008 (8) | 0.42176 (18) | 0.0349 (4) | |
H2A | 0.2983 | 0.6835 | 0.3663 | 0.042* | |
H2B | 0.1381 | 0.7264 | 0.3787 | 0.042* | |
C3 | 0.2608 (2) | 0.70523 (7) | 0.57705 (17) | 0.0289 (4) | |
C4 | 0.36897 (19) | 0.66654 (7) | 0.66698 (17) | 0.0261 (3) | |
C5 | 0.36049 (19) | 0.66757 (7) | 0.81608 (18) | 0.0286 (4) | |
H5 | 0.4335 | 0.6414 | 0.8755 | 0.034* | |
C6 | 0.2487 (2) | 0.70560 (8) | 0.88108 (18) | 0.0321 (4) | |
C7 | 0.1717 (2) | 0.75331 (8) | 0.7957 (2) | 0.0343 (4) | |
H7 | 0.1149 | 0.7862 | 0.8395 | 0.041* | |
C8 | 0.1786 (2) | 0.75250 (7) | 0.64735 (19) | 0.0333 (4) | |
H8 | 0.1255 | 0.7853 | 0.5910 | 0.040* | |
C9 | 0.1892 (2) | 0.68582 (9) | 1.02364 (19) | 0.0395 (4) | |
H9A | 0.1627 | 0.7237 | 1.0789 | 0.047* | |
H9B | 0.2793 | 0.6630 | 1.0808 | 0.047* | |
C10 | 0.0297 (2) | 0.64211 (9) | 1.00303 (18) | 0.0354 (4) | |
H10A | 0.0451 | 0.6059 | 1.0699 | 0.042* | |
H10B | −0.0679 | 0.6661 | 1.0292 | 0.042* | |
C11 | −0.00429 (19) | 0.61792 (7) | 0.84983 (17) | 0.0274 (4) | |
C12 | −0.10858 (19) | 0.65368 (8) | 0.75372 (18) | 0.0304 (4) | |
H12 | −0.1895 | 0.6800 | 0.7910 | 0.036* | |
C13 | −0.09777 (19) | 0.65202 (8) | 0.60648 (18) | 0.0304 (4) | |
H13 | −0.1696 | 0.6774 | 0.5443 | 0.036* | |
C14 | 0.01797 (19) | 0.61324 (7) | 0.54809 (17) | 0.0284 (4) | |
C15 | 0.09165 (18) | 0.56707 (7) | 0.63868 (17) | 0.0257 (3) | |
H15 | 0.1494 | 0.5336 | 0.5979 | 0.031* | |
C16 | 0.08267 (19) | 0.56879 (7) | 0.78843 (17) | 0.0256 (3) | |
C17 | 0.47406 (19) | 0.61790 (7) | 0.60409 (18) | 0.0277 (4) | |
C18 | 0.6381 (2) | 0.52648 (8) | 0.6598 (2) | 0.0368 (4) | |
H18A | 0.5700 | 0.4905 | 0.6250 | 0.044* | |
H18B | 0.7148 | 0.5134 | 0.7422 | 0.044* | |
H18C | 0.7015 | 0.5418 | 0.5819 | 0.044* | |
C19 | 0.1892 (2) | 0.52461 (7) | 0.87962 (18) | 0.0306 (4) | |
C20 | 0.3453 (2) | 0.43088 (9) | 0.8791 (2) | 0.0493 (5) | |
H20A | 0.4503 | 0.4530 | 0.9034 | 0.059* | |
H20B | 0.3638 | 0.3952 | 0.8160 | 0.059* | |
H20C | 0.3023 | 0.4157 | 0.9681 | 0.059* | |
O1 | 0.50458 (16) | 0.61564 (6) | 0.47945 (13) | 0.0393 (3) | |
O2 | 0.53199 (14) | 0.57609 (5) | 0.70449 (12) | 0.0350 (3) | |
O3 | 0.24102 (18) | 0.53320 (7) | 1.00414 (14) | 0.0504 (4) | |
O4 | 0.22660 (16) | 0.47329 (5) | 0.80545 (14) | 0.0406 (3) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0401 (10) | 0.0392 (10) | 0.0270 (9) | −0.0010 (8) | −0.0022 (7) | 0.0005 (7) |
C2 | 0.0357 (9) | 0.0376 (9) | 0.0315 (9) | 0.0017 (7) | 0.0039 (7) | 0.0090 (7) |
C3 | 0.0284 (8) | 0.0248 (8) | 0.0339 (9) | −0.0050 (6) | 0.0050 (7) | 0.0049 (7) |
C4 | 0.0231 (8) | 0.0238 (8) | 0.0313 (8) | −0.0065 (6) | 0.0018 (6) | −0.0003 (6) |
C5 | 0.0250 (8) | 0.0276 (8) | 0.0324 (9) | −0.0062 (6) | −0.0026 (6) | −0.0025 (7) |
C6 | 0.0301 (9) | 0.0334 (9) | 0.0322 (9) | −0.0079 (7) | 0.0005 (7) | −0.0103 (7) |
C7 | 0.0310 (9) | 0.0256 (8) | 0.0467 (10) | −0.0046 (7) | 0.0053 (7) | −0.0102 (7) |
C8 | 0.0313 (9) | 0.0218 (8) | 0.0465 (10) | −0.0019 (7) | 0.0029 (7) | 0.0024 (7) |
C9 | 0.0402 (10) | 0.0466 (11) | 0.0317 (9) | −0.0045 (8) | 0.0025 (7) | −0.0113 (8) |
C10 | 0.0376 (9) | 0.0386 (10) | 0.0314 (9) | −0.0003 (8) | 0.0107 (7) | −0.0033 (7) |
C11 | 0.0239 (8) | 0.0273 (8) | 0.0316 (8) | −0.0041 (6) | 0.0052 (6) | 0.0000 (6) |
C12 | 0.0226 (8) | 0.0260 (8) | 0.0429 (10) | −0.0006 (6) | 0.0046 (7) | −0.0023 (7) |
C13 | 0.0246 (8) | 0.0275 (8) | 0.0375 (9) | −0.0008 (6) | −0.0054 (7) | 0.0031 (7) |
C14 | 0.0264 (8) | 0.0287 (8) | 0.0289 (8) | −0.0061 (6) | −0.0035 (6) | −0.0021 (6) |
C15 | 0.0217 (7) | 0.0230 (8) | 0.0317 (8) | −0.0035 (6) | −0.0007 (6) | −0.0029 (6) |
C16 | 0.0217 (7) | 0.0237 (8) | 0.0312 (8) | −0.0036 (6) | 0.0015 (6) | 0.0011 (6) |
C17 | 0.0232 (8) | 0.0268 (8) | 0.0328 (9) | −0.0062 (6) | 0.0010 (6) | 0.0006 (7) |
C18 | 0.0330 (9) | 0.0285 (9) | 0.0477 (11) | 0.0052 (7) | −0.0019 (8) | −0.0035 (7) |
C19 | 0.0272 (8) | 0.0284 (9) | 0.0360 (9) | −0.0039 (7) | 0.0023 (7) | 0.0055 (7) |
C20 | 0.0418 (11) | 0.0307 (10) | 0.0735 (14) | 0.0082 (8) | −0.0043 (10) | 0.0127 (9) |
O1 | 0.0445 (7) | 0.0407 (7) | 0.0336 (7) | 0.0055 (6) | 0.0082 (5) | −0.0013 (5) |
O2 | 0.0326 (6) | 0.0331 (6) | 0.0392 (7) | 0.0059 (5) | 0.0035 (5) | 0.0030 (5) |
O3 | 0.0589 (9) | 0.0533 (9) | 0.0366 (8) | 0.0130 (7) | −0.0084 (6) | 0.0059 (6) |
O4 | 0.0413 (7) | 0.0259 (6) | 0.0526 (8) | 0.0068 (5) | −0.0071 (6) | 0.0020 (5) |
C1—C2 | 1.588 (3) | C10—H10B | 0.9900 |
C9—C10 | 1.588 (3) | C11—C12 | 1.396 (2) |
C1—C14 | 1.507 (2) | C11—C16 | 1.410 (2) |
C1—H1A | 0.9900 | C12—C13 | 1.378 (2) |
C1—H1B | 0.9900 | C12—H12 | 0.9500 |
C2—C3 | 1.512 (2) | C13—C14 | 1.395 (2) |
C2—H2A | 0.9900 | C13—H13 | 0.9500 |
C2—H2B | 0.9900 | C14—C15 | 1.391 (2) |
C3—C8 | 1.400 (2) | C15—C16 | 1.399 (2) |
C3—C4 | 1.417 (2) | C15—H15 | 0.9500 |
C4—C5 | 1.392 (2) | C16—C19 | 1.487 (2) |
C4—C17 | 1.492 (2) | C17—O1 | 1.206 (2) |
C5—C6 | 1.393 (2) | C17—O2 | 1.341 (2) |
C5—H5 | 0.9500 | C18—O2 | 1.446 (2) |
C6—C7 | 1.399 (3) | C18—H18A | 0.9800 |
C6—C9 | 1.509 (3) | C18—H18B | 0.9800 |
C7—C8 | 1.383 (3) | C18—H18C | 0.9800 |
C7—H7 | 0.9500 | C19—O3 | 1.206 (2) |
C8—H8 | 0.9500 | C19—O4 | 1.341 (2) |
C9—H9A | 0.9900 | C20—O4 | 1.444 (2) |
C9—H9B | 0.9900 | C20—H20A | 0.9800 |
C10—C11 | 1.513 (2) | C20—H20B | 0.9800 |
C10—H10A | 0.9900 | C20—H20C | 0.9800 |
C14—C1—C2 | 111.75 (14) | C11—C10—H10A | 109.0 |
C1—C2—C3 | 112.80 (13) | C9—C10—H10A | 109.0 |
C6—C9—C10 | 112.29 (14) | C11—C10—H10B | 109.0 |
C9—C10—C11 | 112.82 (14) | C9—C10—H10B | 109.0 |
C4—C3—C8 | 115.95 (15) | H10A—C10—H10B | 107.8 |
C5—C6—C7 | 116.73 (16) | C12—C11—C10 | 117.51 (15) |
C12—C11—C16 | 116.18 (15) | C13—C12—C11 | 121.99 (15) |
C13—C14—C15 | 116.68 (15) | C13—C12—H12 | 119.0 |
C2—C3—C4 | 124.32 (15) | C11—C12—H12 | 119.0 |
C10—C11—C16 | 125.28 (15) | C12—C13—C14 | 120.45 (15) |
C14—C1—H1A | 109.3 | C12—C13—H13 | 119.8 |
C2—C1—H1A | 109.3 | C14—C13—H13 | 119.8 |
C14—C1—H1B | 109.3 | C15—C14—C1 | 120.91 (15) |
C2—C1—H1B | 109.3 | C13—C14—C1 | 121.11 (15) |
H1A—C1—H1B | 107.9 | C14—C15—C16 | 121.55 (15) |
C3—C2—H2A | 109.0 | C14—C15—H15 | 119.2 |
C1—C2—H2A | 109.0 | C16—C15—H15 | 119.2 |
C3—C2—H2B | 109.0 | C15—C16—C11 | 119.64 (14) |
C1—C2—H2B | 109.0 | C15—C16—C19 | 117.94 (14) |
H2A—C2—H2B | 107.8 | C11—C16—C19 | 121.61 (15) |
C8—C3—C2 | 118.24 (15) | O1—C17—O2 | 123.40 (15) |
C5—C4—C3 | 119.49 (15) | O1—C17—C4 | 125.26 (15) |
C5—C4—C17 | 118.80 (14) | O2—C17—C4 | 111.34 (14) |
C3—C4—C17 | 121.09 (15) | O2—C18—H18A | 109.5 |
C4—C5—C6 | 122.23 (15) | O2—C18—H18B | 109.5 |
C4—C5—H5 | 118.9 | H18A—C18—H18B | 109.5 |
C6—C5—H5 | 118.9 | O2—C18—H18C | 109.5 |
C5—C6—C9 | 119.36 (16) | H18A—C18—H18C | 109.5 |
C7—C6—C9 | 122.55 (16) | H18B—C18—H18C | 109.5 |
C8—C7—C6 | 119.90 (16) | O3—C19—O4 | 122.70 (15) |
C8—C7—H7 | 120.1 | O3—C19—C16 | 125.58 (16) |
C6—C7—H7 | 120.1 | O4—C19—C16 | 111.69 (14) |
C7—C8—C3 | 122.48 (16) | O4—C20—H20A | 109.5 |
C7—C8—H8 | 118.8 | O4—C20—H20B | 109.5 |
C3—C8—H8 | 118.8 | H20A—C20—H20B | 109.5 |
C6—C9—H9A | 109.1 | O4—C20—H20C | 109.5 |
C10—C9—H9A | 109.1 | H20A—C20—H20C | 109.5 |
C6—C9—H9B | 109.1 | H20B—C20—H20C | 109.5 |
C10—C9—H9B | 109.1 | C17—O2—C18 | 117.65 (13) |
H9A—C9—H9B | 107.9 | C19—O4—C20 | 115.98 (15) |
C14—C1—C2—C3 | 18.7 (2) | C16—C11—C12—C13 | −15.5 (2) |
C1—C2—C3—C8 | −100.08 (18) | C10—C11—C12—C13 | 153.50 (16) |
C1—C2—C3—C4 | 65.4 (2) | C11—C12—C13—C14 | 0.9 (2) |
C8—C3—C4—C5 | 14.2 (2) | C12—C13—C14—C15 | 14.5 (2) |
C2—C3—C4—C5 | −151.63 (15) | C12—C13—C14—C1 | −152.57 (16) |
C8—C3—C4—C17 | −175.00 (13) | C2—C1—C14—C15 | −98.53 (18) |
C2—C3—C4—C17 | 19.2 (2) | C2—C1—C14—C13 | 68.0 (2) |
C3—C4—C5—C6 | −0.1 (2) | C13—C14—C15—C16 | −15.3 (2) |
C17—C4—C5—C6 | −171.10 (14) | C1—C14—C15—C16 | 151.80 (15) |
C4—C5—C6—C7 | −14.4 (2) | C14—C15—C16—C11 | 0.7 (2) |
C4—C5—C6—C9 | 152.62 (15) | C14—C15—C16—C19 | −169.21 (14) |
C5—C6—C7—C8 | 14.4 (2) | C12—C11—C16—C15 | 14.5 (2) |
C9—C6—C7—C8 | −152.20 (16) | C10—C11—C16—C15 | −153.53 (15) |
C6—C7—C8—C3 | −0.1 (2) | C12—C11—C16—C19 | −175.96 (14) |
C4—C3—C8—C7 | −14.3 (2) | C10—C11—C16—C19 | 16.0 (2) |
C2—C3—C8—C7 | 152.41 (16) | C5—C4—C17—O1 | −172.49 (15) |
C5—C6—C9—C10 | −88.23 (19) | C3—C4—C17—O1 | 16.6 (2) |
C7—C6—C9—C10 | 78.0 (2) | C5—C4—C17—O2 | 7.47 (19) |
C6—C9—C10—C11 | 13.0 (2) | C3—C4—C17—O2 | −163.43 (13) |
C9—C10—C11—C12 | −91.10 (19) | C15—C16—C19—O3 | 152.58 (17) |
C9—C10—C11—C16 | 76.8 (2) | C11—C16—C19—O3 | −17.1 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
C18—H18A···O1i | 0.98 | 2.51 | 3.447 (3) | 160 |
C18—H18B···O3ii | 0.98 | 2.55 | 3.426 (3) | 149 |
C20—H20A···O3ii | 0.98 | 2.58 | 3.508 (3) | 157 |
C7—H7···O1iii | 0.95 | 2.66 | 3.598 (2) | 171 |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+1, −y+1, −z+2; (iii) x−1/2, −y+3/2, z+1/2. |
C20H20O4 | F(000) = 344 |
Mr = 324.36 | Dx = 1.346 Mg m−3 |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71073 Å |
a = 7.470 (3) Å | Cell parameters from 49 reflections |
b = 11.287 (4) Å | θ = 10–11.5° |
c = 9.494 (3) Å | µ = 0.09 mm−1 |
β = 90.83 (3)° | T = 178 K |
V = 800.4 (5) Å3 | Tablet, colourless |
Z = 2 | 0.45 × 0.40 × 0.20 mm |
Nicolet R3 diffractometer | Rint = 0.029 |
Radiation source: fine-focus sealed tube | θmax = 27.5°, θmin = 3.3° |
Graphite monochromator | h = −6→9 |
ω scans | k = −10→14 |
3864 measured reflections | l = −12→12 |
1939 independent reflections | 3 standard reflections every 147 reflections |
1692 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)] = 0.036 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.096 | H-atom parameters constrained |
S = 1.04 | w = 1/[σ2(Fo2) + (0.054P)2 + 0.084P] where P = (Fo2 + 2Fc2)/3 |
1939 reflections | (Δ/σ)max = 0.001 |
219 parameters | Δρmax = 0.19 e Å−3 |
1 restraint | Δρmin = −0.19 e Å−3 |
C20H20O4 | V = 800.4 (5) Å3 |
Mr = 324.36 | Z = 2 |
Monoclinic, P21 | Mo Kα radiation |
a = 7.470 (3) Å | µ = 0.09 mm−1 |
b = 11.287 (4) Å | T = 178 K |
c = 9.494 (3) Å | 0.45 × 0.40 × 0.20 mm |
β = 90.83 (3)° |
Nicolet R3 diffractometer | Rint = 0.029 |
3864 measured reflections | 3 standard reflections every 147 reflections |
1939 independent reflections | intensity decay: none |
1692 reflections with I > 2σ(I) |
R[F2 > 2σ(F2)] = 0.036 | 1 restraint |
wR(F2) = 0.096 | H-atom parameters constrained |
S = 1.04 | Δρmax = 0.19 e Å−3 |
1939 reflections | Δρmin = −0.19 e Å−3 |
219 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 Distance 3.3377 (0.0034) C17 - C19 Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane) 5.5425 (0.0072) x + 7.3739 (0.0103) y + 1.3271 (0.0136) z = 1.6064 (0.0058) * -0.0074 (0.0011) C4 * 0.0075 (0.0011) C5 * -0.0075 (0.0011) C7 * 0.0075 (0.0011) C8 0.1575 (0.0033) C3 0.1482 (0.0033) C6 Rms deviation of fitted atoms = 0.0075 5.4728 (0.0074) x + 7.4617 (0.0104) y + 1.4357 (0.0124) z = 4.7371 (0.0058) Angle to previous plane (with approximate e.s.d.) = 0.95 (0.18) * 0.0079 (0.0011) C12 * -0.0079 (0.0011) C13 * 0.0078 (0.0011) C15 * -0.0079 (0.0011) C16 - 0.1585 (0.0033) C11 - 0.1751 (0.0033) C14 Rms deviation of fitted atoms = 0.0079 |
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 | ||
C1 | 0.5437 (3) | 0.0772 (2) | 0.2707 (2) | 0.0294 (5) | |
H1A | 0.6320 | 0.0196 | 0.3085 | 0.037* | |
H1B | 0.5982 | 0.1176 | 0.1893 | 0.037* | |
C2 | 0.3700 (3) | 0.0077 (2) | 0.2183 (3) | 0.0313 (5) | |
H2A | 0.3289 | 0.0408 | 0.1268 | 0.037* | |
H2B | 0.4008 | −0.0767 | 0.2034 | 0.037* | |
C3 | 0.2194 (3) | 0.0161 (2) | 0.3235 (2) | 0.0276 (5) | |
C4 | 0.0804 (3) | 0.1003 (2) | 0.3116 (2) | 0.0248 (5) | |
C5 | −0.0026 (3) | 0.1431 (2) | 0.4320 (2) | 0.0269 (5) | |
H5 | −0.0937 | 0.2014 | 0.4227 | 0.032* | |
C6 | 0.0455 (3) | 0.1018 (2) | 0.5664 (2) | 0.0281 (5) | |
C7 | 0.1514 (3) | 0.0001 (2) | 0.5719 (3) | 0.0320 (5) | |
H7 | 0.1649 | −0.0416 | 0.6583 | 0.037* | |
C8 | 0.2376 (3) | −0.0412 (2) | 0.4527 (3) | 0.0316 (5) | |
H8 | 0.3104 | −0.1100 | 0.4597 | 0.036* | |
C9 | 0.0175 (3) | 0.1779 (3) | 0.6944 (3) | 0.0354 (6) | |
H9A | 0.0297 | 0.1282 | 0.7799 | 0.042* | |
H9B | −0.1058 | 0.2101 | 0.6914 | 0.042* | |
C10 | 0.1551 (3) | 0.2845 (2) | 0.7049 (2) | 0.0329 (5) | |
H10A | 0.0917 | 0.3595 | 0.6835 | 0.040* | |
H10B | 0.2027 | 0.2896 | 0.8026 | 0.040* | |
C11 | 0.3093 (3) | 0.2703 (2) | 0.6050 (2) | 0.0256 (4) | |
C12 | 0.4446 (3) | 0.1881 (2) | 0.6329 (2) | 0.0278 (5) | |
H12 | 0.4720 | 0.1665 | 0.7275 | 0.033* | |
C13 | 0.5397 (3) | 0.1373 (2) | 0.5234 (2) | 0.0264 (5) | |
H13 | 0.6304 | 0.0807 | 0.5442 | 0.033* | |
C14 | 0.5039 (3) | 0.1681 (2) | 0.3833 (2) | 0.0252 (4) | |
C15 | 0.4021 (3) | 0.2717 (2) | 0.3603 (2) | 0.0237 (4) | |
C16 | 0.3042 (3) | 0.3201 (2) | 0.4709 (2) | 0.0240 (4) | |
H16 | 0.2327 | 0.3884 | 0.4541 | 0.028* | |
C17 | 0.0250 (3) | 0.1511 (2) | 0.1720 (2) | 0.0274 (5) | |
C18 | −0.1126 (4) | 0.3139 (3) | 0.0560 (3) | 0.0404 (6) | |
H18A | −0.0271 | 0.3021 | −0.0200 | 0.048* | |
H18B | −0.1308 | 0.3990 | 0.0709 | 0.048* | |
H18C | −0.2270 | 0.2767 | 0.0303 | 0.048* | |
C19 | 0.3844 (3) | 0.3235 (2) | 0.2166 (2) | 0.0274 (5) | |
C20 | 0.3262 (4) | 0.4977 (3) | 0.0876 (3) | 0.0409 (6) | |
H20A | 0.4436 | 0.4984 | 0.0429 | 0.049* | |
H20B | 0.2853 | 0.5793 | 0.1016 | 0.049* | |
H20C | 0.2401 | 0.4555 | 0.0269 | 0.049* | |
O1 | 0.0330 (3) | 0.10000 (18) | 0.06044 (18) | 0.0417 (5) | |
O2 | −0.0430 (2) | 0.26074 (16) | 0.18452 (17) | 0.0336 (4) | |
O3 | 0.4070 (3) | 0.2718 (2) | 0.10715 (18) | 0.0467 (5) | |
O4 | 0.3401 (2) | 0.43852 (16) | 0.22215 (18) | 0.0338 (4) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0252 (11) | 0.0285 (12) | 0.0347 (12) | 0.0014 (9) | 0.0050 (9) | −0.0049 (10) |
C2 | 0.0299 (12) | 0.0287 (12) | 0.0354 (13) | 0.0047 (10) | 0.0009 (9) | −0.0076 (10) |
C3 | 0.0256 (11) | 0.0234 (11) | 0.0338 (12) | −0.0057 (9) | −0.0027 (9) | −0.0046 (9) |
C4 | 0.0225 (10) | 0.0225 (10) | 0.0294 (11) | −0.0036 (9) | −0.0026 (8) | −0.0021 (9) |
C5 | 0.0193 (10) | 0.0297 (12) | 0.0317 (11) | −0.0032 (9) | 0.0000 (8) | 0.0027 (10) |
C6 | 0.0208 (10) | 0.0325 (12) | 0.0312 (11) | −0.0073 (9) | 0.0035 (8) | 0.0044 (10) |
C7 | 0.0294 (11) | 0.0316 (12) | 0.0349 (12) | −0.0076 (10) | −0.0021 (9) | 0.0108 (11) |
C8 | 0.0263 (11) | 0.0231 (11) | 0.0452 (14) | −0.0021 (10) | −0.0028 (10) | 0.0026 (11) |
C9 | 0.0307 (11) | 0.0470 (15) | 0.0287 (11) | −0.0028 (12) | 0.0068 (9) | 0.0052 (11) |
C10 | 0.0361 (12) | 0.0360 (13) | 0.0267 (11) | 0.0024 (11) | 0.0032 (9) | −0.0030 (10) |
C11 | 0.0256 (10) | 0.0229 (10) | 0.0284 (11) | −0.0032 (9) | −0.0002 (8) | −0.0025 (9) |
C12 | 0.0267 (11) | 0.0299 (12) | 0.0268 (11) | −0.0043 (10) | −0.0040 (9) | 0.0026 (9) |
C13 | 0.0209 (10) | 0.0244 (11) | 0.0338 (11) | 0.0003 (9) | −0.0016 (8) | 0.0015 (9) |
C14 | 0.0193 (9) | 0.0243 (10) | 0.0322 (11) | −0.0033 (9) | 0.0020 (8) | 0.0001 (10) |
C15 | 0.0217 (9) | 0.0218 (10) | 0.0276 (10) | −0.0041 (9) | −0.0009 (8) | 0.0000 (9) |
C16 | 0.0233 (10) | 0.0204 (10) | 0.0283 (11) | −0.0026 (9) | −0.0013 (8) | −0.0022 (9) |
C17 | 0.0243 (10) | 0.0294 (12) | 0.0285 (11) | −0.0039 (10) | −0.0009 (8) | −0.0030 (10) |
C18 | 0.0531 (16) | 0.0387 (14) | 0.0292 (12) | 0.0080 (13) | 0.0000 (11) | 0.0054 (11) |
C19 | 0.0279 (11) | 0.0266 (11) | 0.0276 (11) | −0.0021 (10) | 0.0023 (8) | 0.0015 (10) |
C20 | 0.0519 (15) | 0.0379 (14) | 0.0327 (13) | 0.0005 (13) | −0.0043 (11) | 0.0105 (12) |
O1 | 0.0512 (11) | 0.0421 (11) | 0.0313 (9) | 0.0071 (9) | −0.0109 (8) | −0.0123 (8) |
O2 | 0.0442 (10) | 0.0291 (9) | 0.0274 (8) | 0.0055 (8) | −0.0007 (7) | 0.0008 (7) |
O3 | 0.0744 (13) | 0.0374 (10) | 0.0283 (9) | 0.0073 (11) | 0.0043 (8) | −0.0014 (9) |
O4 | 0.0463 (10) | 0.0264 (9) | 0.0286 (9) | 0.0034 (8) | −0.0016 (7) | 0.0049 (7) |
C1—C2 | 1.590 (3) | C10—H10B | 0.9900 |
C9—C10 | 1.584 (4) | C11—C16 | 1.391 (3) |
C1—C14 | 1.514 (3) | C11—C12 | 1.395 (3) |
C1—H1A | 0.9900 | C12—C13 | 1.391 (3) |
C1—H1B | 0.9900 | C12—H12 | 0.9500 |
C2—C3 | 1.518 (3) | C13—C14 | 1.397 (3) |
C2—H2A | 0.9900 | C13—H13 | 0.9500 |
C2—H2B | 0.9900 | C14—C15 | 1.410 (3) |
C3—C8 | 1.392 (3) | C15—C16 | 1.400 (3) |
C3—C4 | 1.411 (3) | C15—C19 | 1.488 (3) |
C4—C5 | 1.395 (3) | C16—H16 | 0.9500 |
C4—C17 | 1.497 (3) | C17—O1 | 1.208 (3) |
C5—C6 | 1.400 (3) | C17—O2 | 1.344 (3) |
C5—H5 | 0.9500 | C18—O2 | 1.449 (3) |
C6—C7 | 1.395 (4) | C18—H18A | 0.9800 |
C6—C9 | 1.505 (4) | C18—H18B | 0.9800 |
C7—C8 | 1.390 (4) | C18—H18C | 0.9800 |
C7—H7 | 0.9500 | C19—O3 | 1.206 (3) |
C8—H8 | 0.9500 | C19—O4 | 1.341 (3) |
C9—H9A | 0.9900 | C20—O4 | 1.444 (3) |
C9—H9B | 0.9900 | C20—H20A | 0.9800 |
C10—C11 | 1.511 (3) | C20—H20B | 0.9800 |
C10—H10A | 0.9900 | C20—H20C | 0.9800 |
C14—C1—C2 | 112.82 (18) | C11—C10—H10A | 109.1 |
C1—C2—C3 | 111.86 (19) | C9—C10—H10A | 109.1 |
C6—C9—C10 | 112.77 (18) | C11—C10—H10B | 109.1 |
C9—C10—C11 | 112.3 (2) | C9—C10—H10B | 109.1 |
C4—C3—C8 | 116.5 (2) | H10A—C10—H10B | 107.9 |
C5—C6—C7 | 116.5 (2) | C16—C11—C10 | 121.4 (2) |
C12—C11—C16 | 116.9 (2) | C12—C11—C10 | 120.5 (2) |
C13—C14—C15 | 116.7 (2) | C13—C12—C11 | 120.6 (2) |
C2—C3—C4 | 122.7 (2) | C13—C12—H12 | 119.7 |
C1—C14—C15 | 124.3 (2) | C11—C12—H12 | 119.7 |
C14—C1—H1A | 109.0 | C12—C13—C14 | 121.1 (2) |
C2—C1—H1A | 109.0 | C12—C13—H13 | 119.5 |
C14—C1—H1B | 109.0 | C14—C13—H13 | 119.5 |
C2—C1—H1B | 109.0 | C13—C14—C1 | 117.8 (2) |
H1A—C1—H1B | 107.8 | C16—C15—C14 | 119.6 (2) |
C3—C2—H2A | 109.2 | C16—C15—C19 | 119.6 (2) |
C1—C2—H2A | 109.2 | C14—C15—C19 | 120.6 (2) |
C3—C2—H2B | 109.2 | C11—C16—C15 | 121.4 (2) |
C1—C2—H2B | 109.2 | C11—C16—H16 | 119.3 |
H2A—C2—H2B | 107.9 | C15—C16—H16 | 119.3 |
C8—C3—C2 | 119.1 (2) | O1—C17—O2 | 122.7 (2) |
C5—C4—C3 | 120.2 (2) | O1—C17—C4 | 125.2 (2) |
C5—C4—C17 | 118.2 (2) | O2—C17—C4 | 111.98 (19) |
C3—C4—C17 | 121.5 (2) | O2—C18—H18A | 109.5 |
C4—C5—C6 | 121.4 (2) | O2—C18—H18B | 109.5 |
C4—C5—H5 | 119.3 | H18A—C18—H18B | 109.5 |
C6—C5—H5 | 119.3 | O2—C18—H18C | 109.5 |
C7—C6—C9 | 121.7 (2) | H18A—C18—H18C | 109.5 |
C5—C6—C9 | 120.6 (2) | H18B—C18—H18C | 109.5 |
C8—C7—C6 | 121.0 (2) | O3—C19—O4 | 122.7 (2) |
C8—C7—H7 | 119.5 | O3—C19—C15 | 126.0 (2) |
C6—C7—H7 | 119.5 | O4—C19—C15 | 111.3 (2) |
C7—C8—C3 | 121.4 (2) | O4—C20—H20A | 109.5 |
C7—C8—H8 | 119.3 | O4—C20—H20B | 109.5 |
C3—C8—H8 | 119.3 | H20A—C20—H20B | 109.5 |
C6—C9—H9A | 109.0 | O4—C20—H20C | 109.5 |
C10—C9—H9A | 109.0 | H20A—C20—H20C | 109.5 |
C6—C9—H9B | 109.0 | H20B—C20—H20C | 109.5 |
C10—C9—H9B | 109.0 | C17—O2—C18 | 116.01 (19) |
H9A—C9—H9B | 107.8 | C19—O4—C20 | 115.3 (2) |
C14—C1—C2—C3 | −19.6 (3) | C12—C13—C14—C15 | 15.3 (3) |
C1—C2—C3—C8 | −68.5 (3) | C12—C13—C14—C1 | −152.7 (2) |
C1—C2—C3—C4 | 96.4 (3) | C2—C1—C14—C13 | 99.8 (2) |
C8—C3—C4—C5 | 15.0 (3) | C2—C1—C14—C15 | −67.3 (3) |
C2—C3—C4—C5 | −150.3 (2) | C13—C14—C15—C16 | −16.6 (3) |
C8—C3—C4—C17 | −168.4 (2) | C1—C14—C15—C16 | 150.6 (2) |
C2—C3—C4—C17 | 26.3 (3) | C13—C14—C15—C19 | 169.1 (2) |
C3—C4—C5—C6 | −1.7 (3) | C1—C14—C15—C19 | −23.7 (3) |
C17—C4—C5—C6 | −178.4 (2) | C12—C11—C16—C15 | 14.0 (3) |
C4—C5—C6—C7 | −12.9 (3) | C10—C11—C16—C15 | −153.5 (2) |
C4—C5—C6—C9 | 154.4 (2) | C14—C15—C16—C11 | 2.1 (3) |
C5—C6—C7—C8 | 14.3 (3) | C19—C15—C16—C11 | 176.4 (2) |
C9—C6—C7—C8 | −152.9 (2) | C5—C4—C17—O1 | −152.6 (2) |
C6—C7—C8—C3 | −1.0 (4) | C3—C4—C17—O1 | 30.7 (3) |
C4—C3—C8—C7 | −13.8 (3) | C5—C4—C17—O2 | 24.9 (3) |
C2—C3—C8—C7 | 152.1 (2) | C3—C4—C17—O2 | −151.8 (2) |
C7—C6—C9—C10 | 93.8 (3) | C16—C15—C19—O3 | −153.0 (2) |
C5—C6—C9—C10 | −72.9 (3) | C14—C15—C19—O3 | 21.3 (4) |
C6—C9—C10—C11 | −13.3 (3) | C16—C15—C19—O4 | 27.5 (3) |
C9—C10—C11—C16 | 93.0 (3) | C14—C15—C19—O4 | −158.2 (2) |
C9—C10—C11—C12 | −74.1 (3) | O1—C17—O2—C18 | 1.9 (3) |
C16—C11—C12—C13 | −15.4 (3) | C4—C17—O2—C18 | −175.6 (2) |
C10—C11—C12—C13 | 152.2 (2) | O3—C19—O4—C20 | −1.7 (3) |
C11—C12—C13—C14 | 0.7 (3) | C15—C19—O4—C20 | 177.9 (2) |
C20H20O4 | F(000) = 344 |
Mr = 324.36 | Dx = 1.378 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 8.699 (2) Å | Cell parameters from 50 reflections |
b = 11.790 (3) Å | θ = 10–12° |
c = 7.628 (2) Å | µ = 0.10 mm−1 |
β = 91.90 (2)° | T = 178 K |
V = 781.9 (3) Å3 | Tablet, colourless |
Z = 2 | 0.7 × 0.4 × 0.2 mm |
Nicolet R3 diffractometer | Rint = 0.016 |
Radiation source: fine-focus sealed tube | θmax = 27.5°, θmin = 3.2° |
Graphite monochromator | h = −11→11 |
ω scans | k = −15→0 |
2989 measured reflections | l = −9→9 |
1789 independent reflections | 3 standard reflections every 147 reflections |
1390 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)] = 0.045 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.131 | H-atom parameters constrained |
S = 1.06 | w = 1/[σ2(Fo2) + (0.064P)2 + 0.341P] where P = (Fo2 + 2Fc2)/3 |
1789 reflections | (Δ/σ)max = 0.002 |
110 parameters | Δρmax = 0.27 e Å−3 |
0 restraints | Δρmin = −0.24 e Å−3 |
C20H20O4 | V = 781.9 (3) Å3 |
Mr = 324.36 | Z = 2 |
Monoclinic, P21/c | Mo Kα radiation |
a = 8.699 (2) Å | µ = 0.10 mm−1 |
b = 11.790 (3) Å | T = 178 K |
c = 7.628 (2) Å | 0.7 × 0.4 × 0.2 mm |
β = 91.90 (2)° |
Nicolet R3 diffractometer | Rint = 0.016 |
2989 measured reflections | 3 standard reflections every 147 reflections |
1789 independent reflections | intensity decay: none |
1390 reflections with I > 2σ(I) |
R[F2 > 2σ(F2)] = 0.045 | 0 restraints |
wR(F2) = 0.131 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.27 e Å−3 |
1789 reflections | Δρmin = −0.24 e Å−3 |
110 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. Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane) 1.3508 (0.0077) x + 8.1080 (0.0077) y + 5.3674 (0.0057) z = 8.9632 (0.0049) * 0.0004 (0.0007) C4 * -0.0004 (0.0007) C5 * 0.0004 (0.0007) C7 * -0.0004 (0.0007) C8 - 0.1745 (0.0023) C3 - 0.1651 (0.0023) C6 Rms deviation of fitted atoms = 0.0004 |
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 | ||
C1 | 0.74393 (18) | 0.64368 (14) | 0.3711 (2) | 0.0283 (4) | |
H1A | 0.8518 | 0.6268 | 0.4077 | 0.034* | |
H1B | 0.7392 | 0.7236 | 0.3316 | 0.034* | |
C2 | 0.30567 (19) | 0.43655 (14) | 0.7880 (2) | 0.0297 (4) | |
H2A | 0.2129 | 0.4734 | 0.8337 | 0.036* | |
H2B | 0.3528 | 0.3900 | 0.8834 | 0.036* | |
C3 | 0.41881 (18) | 0.52714 (13) | 0.7357 (2) | 0.0255 (3) | |
C4 | 0.38195 (17) | 0.62310 (13) | 0.6326 (2) | 0.0242 (3) | |
C5 | 0.49389 (18) | 0.67294 (13) | 0.5290 (2) | 0.0247 (3) | |
H5 | 0.4679 | 0.7374 | 0.4594 | 0.030* | |
C6 | 0.64258 (17) | 0.62919 (12) | 0.5270 (2) | 0.0240 (3) | |
C7 | 0.68551 (18) | 0.55385 (13) | 0.6608 (2) | 0.0263 (3) | |
H7 | 0.7911 | 0.5364 | 0.6819 | 0.032* | |
C8 | 0.57554 (18) | 0.50420 (13) | 0.7634 (2) | 0.0271 (4) | |
H8 | 0.6072 | 0.4535 | 0.8544 | 0.032* | |
C9 | 0.22073 (18) | 0.66526 (14) | 0.6167 (2) | 0.0277 (4) | |
C10 | 0.0661 (2) | 0.82925 (16) | 0.5719 (3) | 0.0384 (4) | |
H10A | 0.0088 | 0.8051 | 0.4655 | 0.046* | |
H10B | 0.0778 | 0.9119 | 0.5710 | 0.046* | |
H10C | 0.0098 | 0.8064 | 0.6753 | 0.046* | |
O1 | 0.10599 (14) | 0.61052 (11) | 0.6380 (2) | 0.0470 (4) | |
O2 | 0.21601 (13) | 0.77660 (10) | 0.57744 (18) | 0.0362 (3) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0257 (7) | 0.0258 (8) | 0.0334 (9) | −0.0040 (6) | 0.0033 (6) | 0.0025 (6) |
C2 | 0.0335 (8) | 0.0266 (8) | 0.0295 (8) | −0.0010 (6) | 0.0076 (7) | 0.0019 (7) |
C3 | 0.0302 (8) | 0.0255 (8) | 0.0210 (7) | −0.0025 (6) | 0.0041 (6) | −0.0042 (6) |
C4 | 0.0255 (7) | 0.0223 (7) | 0.0248 (8) | −0.0001 (6) | 0.0008 (6) | −0.0053 (6) |
C5 | 0.0275 (7) | 0.0198 (7) | 0.0267 (8) | −0.0010 (6) | −0.0016 (6) | −0.0019 (6) |
C6 | 0.0237 (7) | 0.0207 (7) | 0.0274 (8) | −0.0042 (6) | −0.0009 (6) | −0.0043 (6) |
C7 | 0.0250 (7) | 0.0260 (8) | 0.0276 (8) | −0.0007 (6) | −0.0036 (6) | −0.0051 (6) |
C8 | 0.0326 (8) | 0.0262 (8) | 0.0223 (8) | 0.0015 (6) | −0.0025 (6) | −0.0018 (6) |
C9 | 0.0272 (8) | 0.0256 (8) | 0.0302 (8) | 0.0004 (6) | 0.0031 (6) | −0.0046 (6) |
C10 | 0.0310 (9) | 0.0329 (9) | 0.0516 (11) | 0.0085 (7) | 0.0052 (8) | −0.0002 (8) |
O1 | 0.0272 (6) | 0.0337 (7) | 0.0804 (11) | −0.0022 (5) | 0.0050 (6) | 0.0044 (7) |
O2 | 0.0268 (6) | 0.0263 (6) | 0.0560 (8) | 0.0043 (5) | 0.0053 (5) | 0.0018 (5) |
C1—C6 | 1.513 (2) | C5—H5 | 0.9500 |
C1—C2i | 1.587 (2) | C6—C7 | 1.395 (2) |
C1—H1A | 0.9900 | C7—C8 | 1.385 (2) |
C1—H1B | 0.9900 | C7—H7 | 0.9500 |
C2—C3 | 1.515 (2) | C8—H8 | 0.9500 |
C2—H2A | 0.9900 | C9—O1 | 1.204 (2) |
C2—H2B | 0.9900 | C9—O2 | 1.347 (2) |
C3—C8 | 1.399 (2) | C10—O2 | 1.444 (2) |
C3—C4 | 1.409 (2) | C10—H10A | 0.9800 |
C4—C5 | 1.403 (2) | C10—H10B | 0.9800 |
C4—C9 | 1.489 (2) | C10—H10C | 0.9800 |
C5—C6 | 1.393 (2) | ||
C6—C1—C2i | 112.51 (12) | C6—C5—H5 | 119.6 |
C3—C2—C1i | 112.44 (13) | C4—C5—H5 | 119.6 |
C4—C3—C8 | 116.23 (14) | C5—C6—C1 | 122.17 (14) |
C5—C6—C7 | 116.99 (14) | C7—C6—C1 | 119.88 (14) |
C2—C3—C4 | 125.12 (14) | C8—C7—C6 | 120.62 (14) |
C6—C1—H1A | 109.1 | C8—C7—H7 | 119.7 |
C2i—C1—H1A | 109.1 | C6—C7—H7 | 119.7 |
C6—C1—H1B | 109.1 | C7—C8—C3 | 121.39 (15) |
C2i—C1—H1B | 109.1 | C7—C8—H8 | 119.3 |
H1A—C1—H1B | 107.8 | C3—C8—H8 | 119.3 |
C3—C2—H2A | 109.1 | O1—C9—O2 | 122.22 (15) |
C1i—C2—H2A | 109.1 | O1—C9—C4 | 126.35 (16) |
C3—C2—H2B | 109.1 | O2—C9—C4 | 111.42 (13) |
C1i—C2—H2B | 109.1 | O2—C10—H10A | 109.5 |
H2A—C2—H2B | 107.8 | O2—C10—H10B | 109.5 |
C8—C3—C2 | 117.55 (15) | H10A—C10—H10B | 109.5 |
C5—C4—C3 | 120.08 (14) | O2—C10—H10C | 109.5 |
C5—C4—C9 | 118.93 (14) | H10A—C10—H10C | 109.5 |
C3—C4—C9 | 120.65 (14) | H10B—C10—H10C | 109.5 |
C6—C5—C4 | 120.88 (15) | C9—O2—C10 | 116.51 (13) |
C1i—C2—C3—C8 | −94.36 (17) | C5—C6—C7—C8 | 15.3 (2) |
C1i—C2—C3—C4 | 73.2 (2) | C1—C6—C7—C8 | −153.69 (15) |
C8—C3—C4—C5 | 15.8 (2) | C6—C7—C8—C3 | 0.4 (2) |
C2—C3—C4—C5 | −151.87 (15) | C4—C3—C8—C7 | −16.0 (2) |
C8—C3—C4—C9 | −170.88 (14) | C2—C3—C8—C7 | 152.69 (15) |
C2—C3—C4—C9 | 21.4 (2) | C5—C4—C9—O1 | 149.52 (18) |
C3—C4—C5—C6 | −0.4 (2) | C3—C4—C9—O1 | −23.9 (3) |
C9—C4—C5—C6 | −173.78 (14) | C5—C4—C9—O2 | −31.7 (2) |
C4—C5—C6—C7 | −15.3 (2) | C3—C4—C9—O2 | 154.94 (15) |
C4—C5—C6—C1 | 153.44 (14) | O1—C9—O2—C10 | 3.5 (3) |
C2i—C1—C6—C5 | −74.91 (18) | C4—C9—O2—C10 | −175.40 (14) |
C2i—C1—C6—C7 | 93.50 (18) | C3—C2—C1i—C6i | 12.69 (19) |
Symmetry code: (i) −x+1, −y+1, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
C8—H8···O2ii | 0.95 | 2.63 | 3.438 (2) | 143 |
Symmetry code: (ii) −x+1, y−1/2, −z+3/2. |
Experimental details
(IVa) | (IVb) | (IVd) | |
Crystal data | |||
Chemical formula | C20H20O4 | C20H20O4 | C20H20O4 |
Mr | 324.36 | 324.36 | 324.36 |
Crystal system, space group | Monoclinic, P21/n | Monoclinic, P21 | Monoclinic, P21/c |
Temperature (K) | 178 | 178 | 178 |
a, b, c (Å) | 8.096 (4), 21.282 (11), 9.281 (5) | 7.470 (3), 11.287 (4), 9.494 (3) | 8.699 (2), 11.790 (3), 7.628 (2) |
β (°) | 95.28 (4) | 90.83 (3) | 91.90 (2) |
V (Å3) | 1592.3 (14) | 800.4 (5) | 781.9 (3) |
Z | 4 | 2 | 2 |
Radiation type | Mo Kα | Mo Kα | Mo Kα |
µ (mm−1) | 0.09 | 0.09 | 0.10 |
Crystal size (mm) | 0.7 × 0.6 × 0.5 | 0.45 × 0.40 × 0.20 | 0.7 × 0.4 × 0.2 |
Data collection | |||
Diffractometer | Nicolet R3 diffractometer | Nicolet R3 diffractometer | Nicolet R3 diffractometer |
Absorption correction | – | – | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2954, 2767, 2296 | 3864, 1939, 1692 | 2989, 1789, 1390 |
Rint | 0.010 | 0.029 | 0.016 |
(sin θ/λ)max (Å−1) | 0.595 | 0.650 | 0.649 |
Refinement | |||
R[F2 > 2σ(F2)], wR(F2), S | 0.041, 0.119, 1.05 | 0.036, 0.096, 1.04 | 0.045, 0.131, 1.06 |
No. of reflections | 2767 | 1939 | 1789 |
No. of parameters | 219 | 219 | 110 |
No. of restraints | 0 | 1 | 0 |
H-atom treatment | H-atom parameters constrained | H-atom parameters constrained | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.23, −0.20 | 0.19, −0.19 | 0.27, −0.24 |
Computer programs: P3 Software (Nicolet, 1987), P3 Software, XDISK (Nicolet, 1987), SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), XP (Siemens, 1994), SHELXL97.
D—H···A | D—H | H···A | D···A | D—H···A |
C18—H18A···O1i | 0.98 | 2.51 | 3.447 (3) | 160 |
C18—H18B···O3ii | 0.98 | 2.55 | 3.426 (3) | 149 |
C20—H20A···O3ii | 0.98 | 2.58 | 3.508 (3) | 157 |
C7—H7···O1iii | 0.95 | 2.66 | 3.598 (2) | 171 |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+1, −y+1, −z+2; (iii) x−1/2, −y+3/2, z+1/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
C8—H8···O2i | 0.95 | 2.63 | 3.438 (2) | 143 |
Symmetry code: (i) −x+1, y−1/2, −z+3/2. |
(IVa) | (IVb) | (IVd) | |
C1-C2 | 1.588 (3) | 1.590 (3) | 1.587 (2)a |
C9-C10 | 1.588 (3) | 1.584 (4) | |
C14-C1-C2 | 111.75 (14) | 112.82 (18) | |
C1-C2-C3 | 112.80 (13) | 111.86 (19) | 112.44 (13)b |
C6-C9-C10 | 112.29 (14) | 112.77 (18) | |
C9-C10-C11 | 112.82 (14) | 112.3 (2) | |
C4-C3-C8 | 115.95 (15) | 116.5 (2) | 116.23 (14) |
C5-C6-C7 | 116.73 (16) | 116.5 (2) | 116.99 (14) |
C12-C11-C16 | 116.18 (15) | 116.9 (2) | |
C13-C14-C15 | 116.68 (15) | 116.7 (2) | |
C2-C3-C4 | 124.32 (15) | 122.7 (2) | 125.12 (14) |
C10-C11-C16 | 125.28 (15) | ||
C1-C14-C15 | 124.3 (2) | ||
C6-C1-C2 | 112.51 (12)a | ||
C3-C4-C17-O1 | 16.6 (2) | 30.7 (3) | |
C11-C16-C19-O3 | -17.1 (3) | ||
C14-C15-C19-O3 | 21.3 (4) | ||
C4-C17-O2-C18 | -175.6 (2) | ||
C15-C19-O4-C20 | 177.9 (2) | ||
C3-C4-C9-O1 | -23.9 (3) | ||
C4-C9-O2-C10 | -175.40 (14) |
Notes: (a) C2 at (1 - x, 1 - y, 1 - z) for (IVd); (b) C1 at (1 - x, 1 - y, 1 - z) for (IVd). |
When triple-bond dienophiles bearing electron-withdrawing groups are added to 1,2,4,5-hexatetraene, (I), a Diels-Alder reaction occurs, yielding a p-xylylene (p-quinodimethane) intermediate that subsequently dimerizes to a derivative of [2.2]paracyclophane (Hopf, 1972). With an unsymmetrically substituted dienophile, (II), the initial [2 + 4] cycloadduct is the monofunctionalized p-xylylene (III), which has four potential dimerization modes, yielding the isomeric disubstituted cyclophane derivatives, (IVa)-(IVd) (Hopf et al., 1978). We have carried out this addition with methyl propiolate for (II), i.e. with R = CO2CH3, and have obtained the expected mixture of isomeric bis(methoxycarbonyl)[2.2]paracyclophanes: 4,16-, (IVa) (the chiral pseudo-ortho isomer), 4,15-, (IVb) (pseudo-gem, achiral), 4,13-, (IVc) (pseudo-meta, chiral) and 4,12-, (IVd) (pseudo-para, achiral). We are interested in the structures of [2.2]paracyclophane derivatives (for recent examples see Jones et al., 2002; Focken et al., 2001), and report here the structures of (IVa), (IVb) and (IVd); despite repeated attempts, we were unable to obtain good single crystals of (IVc). \sch
All three compounds crystallize in the monoclinic system. By chance, (IVb) and (IVd) have closely similar unit-cell dimensions, although (IVb) has Z' = 1 in P21 and (IVd) has Z' = 1/2 (inversion symmetry) in P21/c. The molecules are shown in Figs. 1–3; (IVa) has approximate twofold and (IVb) approximate mirror symmetry.
The three isomers show features typical of [2.2]paracyclophane structures. The flattened boat form of the rings is observed in each case; atoms C3, C6, C11 and C14 are displaced by 0.157 (2), 0.156 (2), 0.165 (2) and 0.161 (2) Å, respectively, for (IVa), 0.158 (3), 0.148 (3), 0.159 (3) and 0.175 (3) Å, respectively, for (IVb), and atoms C3 and C6 by 0.175 (2) and 0.165 (2) Å, respectively, for (IVd), from the plane of the remaining four ring atoms (respective mean deviations are 0.002, 0.003, 0.008, 0.008 and 0.0004 Å Please clarify what these five values relate to). The two planes thus generated in each molecule are essentially parallel, with interplanar angles all <1° [zero in (IVd), by symmetry]. The C1—C2 and C9—C10 bridgehead bonds are lengthened to 1.588 (3) Å [(IVa), × 2], 1.590 (3) and 1.584 (3) Å [(IVb)], and 1.587 (2) Å [(IVd)]. The ring angles at the bridgeheads are all significantly less than 120° (Tables 1–3).
The four non-bridgehead atoms of each ring may also be used to calculate a centroid, Cg. Torsion angles such as C3—Cg1—Cg2—C14 show that the rings are mutually rotated by ca 2.5° in (IVa) and 6.4° in (IVb); in (IVd), the values are zero by symmetry.
The methoxycarbonyl groups all adopt a similar conformation, in which the C═ O bond is directed outwards towards the bridge [absolute C(bridgehead)-C—C═O torsion angles 16–31°] and the substituent is extended [absolute C—C—O—C(methyl) torsion angles 173–180°]. There appears to be some repulsive steric interaction between the carbonyl O atoms and the corresponding bridge regions, because the angles from the substituent-bearing C atom through the bridgehead to the bridge are all appreciably greater than 120° (Tables 1–3). The pseudo-geminal subsitution pattern in (IVb) is associated with a close approach of 3.338 (3) Å between the substituent atoms C17 and C19. This relaxes to 4.109 (3) Å in the pseudo-ortho (IVa).
The crystal packing of (IVa) (Fig. 4) involves three weak hydrogen bonds of the form C(methyl)-H···O(carbonyl) that connect the molecules into ribbons parallel to the z axis. The ribbons, in turn, form layers parallel to the ac plane, with adjacent planes being connected by a fourth weak C7—H7···O1 hydrogen bond.
The packing of (IVb) involves no weak C—H···O hydrogen bonds, but the ring centroids Cg1 (C11–16) and Cg2 (C3–8) are involved in C8—H8···Cg1 [H···Cg1 2.78 Å, angle 167°, symmetry code 1 - x, y - 1/2, 1 - z) and C10—H10···Cg2 [H···Cg2 2.95 Å, angle 166°, symmetry code -x, 1/2 + y, 1 - z) contacts that might be classified as C—H···π interactions. The overall effect is to connect the molecules in layers parallel to ab (Fig. 5).
The packing of (IVd), like that of (IVa), is determined by C—H···O(carbonyl) interactions, which link the molecules to form layers parallel to bc (Fig. 6).