Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270103024521/sk1674sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270103024521/sk1674Isup2.hkl |
CCDC reference: 231086
The title compound was prepared according to previously described procedures, starting from formylation of cholic acid (Tserng & Klein, 1977) with formic and perchoric acids, followed by oxidative decarboxylation (Concépcion et al., 1986) with iodosobenzene diacetate, selective 3α-deformylation with sodium acetate in methanol, and finally a C-3 Mitsunobu inversion (Bose et al., 1973) with formate, diethyl azodicarboxylate and triphenylphosphine. Crystals siutable for X-ray analysis were obtained from an ethyl acetate solution by slow evaporation. 3β,7α,12α-triformyloxy-24-nor-5β-chol-22-ene: 1H NMR (300 MHz, CDCl3): δ 8.17 (1H, s), 8.09 (1H, s), 8.05 (1H, s), 5.67–5.55 (1H, m), 5.27 (1H, br t), 5.16 (1H, br s), 5.07 (1H, d, J=2.4 Hz), 4.91 (1H, dd, J=17.1; 1.8 Hz), 4.83 (1H, dd, J=10.2; 1.8 Hz), 0.98 (3H, s), 0.95 (3H, d, J=6.6 Hz), 0,78 (3H, s); 13C NMR (75.25 MHz, CDCl3): δ 160.7, 160.5, 144.2, 112.3, 75.2, 71.0, 70.1, 46.8, 45.0, 43.0, 40.5, 37.7, 36.3, 34.5, 32.7, 30.9, 30.1, 28.1, 27.3, 25.8, 24.7, 22.7, 19.5, 12.3.
All H atoms were refined as riding on their parent atoms, using SHELXL97 (Sheldrick, 1997) defaults. Friedel pairs were merged because the anomalous dispersion of the light atoms at the Cu Kα wavelength was negligeable, and thus the absolute configuration was not determined from the X-ray data. However, the configuration was known from the synthesis route.
Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software (Enraf-Nonius, 1989); data reduction: PLATON (Spek,2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson,1976); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).
C26H38O6 | F(000) = 968 |
Mr = 446.56 | Dx = 1.221 Mg m−3 |
Orthorhombic, P212121 | Cu Kα radiation, λ = 1.54180 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 25 reflections |
a = 7.365 (3) Å | θ = 22.7–28.7° |
b = 15.5549 (12) Å | µ = 0.69 mm−1 |
c = 21.199 (4) Å | T = 293 K |
V = 2428.6 (10) Å3 | Prism, colourless |
Z = 4 | 0.37 × 0.24 × 0.24 mm |
Enraf–Nonius MACH-3 diffractometer | 2293 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.031 |
Graphite monochromator | θmax = 71.9°, θmin = 4.2° |
profile data from ω–2θ scans | h = 0→9 |
Absorption correction: ψ scan North et al., 1968 | k = 0→19 |
Tmin = 0.744, Tmax = 0.847 | l = −26→26 |
4523 measured reflections | 3 standard reflections every 200 reflections |
2731 independent reflections | intensity decay: 9.9% |
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)] = 0.035 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.101 | H-atom parameters constrained |
S = 1.03 | w = 1/[σ2(Fo2) + (0.0653P)2 + 0.1429P] where P = (Fo2 + 2Fc2)/3 |
2731 reflections | (Δ/σ)max < 0.001 |
292 parameters | Δρmax = 0.15 e Å−3 |
0 restraints | Δρmin = −0.13 e Å−3 |
C26H38O6 | V = 2428.6 (10) Å3 |
Mr = 446.56 | Z = 4 |
Orthorhombic, P212121 | Cu Kα radiation |
a = 7.365 (3) Å | µ = 0.69 mm−1 |
b = 15.5549 (12) Å | T = 293 K |
c = 21.199 (4) Å | 0.37 × 0.24 × 0.24 mm |
Enraf–Nonius MACH-3 diffractometer | 2293 reflections with I > 2σ(I) |
Absorption correction: ψ scan North et al., 1968 | Rint = 0.031 |
Tmin = 0.744, Tmax = 0.847 | 3 standard reflections every 200 reflections |
4523 measured reflections | intensity decay: 9.9% |
2731 independent reflections |
R[F2 > 2σ(F2)] = 0.035 | 0 restraints |
wR(F2) = 0.101 | H-atom parameters constrained |
S = 1.03 | Δρmax = 0.15 e Å−3 |
2731 reflections | Δρmin = −0.13 e Å−3 |
292 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. |
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 | ||
O3 | 0.0370 (3) | 0.24038 (11) | 0.37737 (8) | 0.0618 (4) | |
O7 | 0.4243 (2) | 0.50124 (10) | 0.26668 (7) | 0.0508 (4) | |
O12 | 0.5049 (2) | 0.31762 (9) | 0.09711 (7) | 0.0514 (4) | |
O31 | 0.1860 (4) | 0.27531 (13) | 0.46646 (9) | 0.0798 (6) | |
O71 | 0.4452 (5) | 0.63027 (15) | 0.31288 (13) | 0.1208 (11) | |
O121 | 0.4815 (4) | 0.20550 (12) | 0.03007 (11) | 0.0856 (7) | |
C1 | 0.0132 (4) | 0.25933 (16) | 0.23814 (12) | 0.0602 (6) | |
H1A | −0.1000 | 0.2495 | 0.2604 | 0.090* | |
H1B | 0.0045 | 0.2307 | 0.1976 | 0.090* | |
C2 | 0.1675 (4) | 0.21842 (14) | 0.27578 (12) | 0.0598 (6) | |
H2A | 0.1404 | 0.1581 | 0.2826 | 0.090* | |
H2B | 0.2788 | 0.2219 | 0.2514 | 0.090* | |
C3 | 0.1960 (3) | 0.26166 (14) | 0.33864 (11) | 0.0514 (5) | |
H3 | 0.3055 | 0.2384 | 0.3586 | 0.062* | |
C4 | 0.2162 (3) | 0.35778 (13) | 0.33076 (10) | 0.0463 (5) | |
H4A | 0.3319 | 0.3694 | 0.3106 | 0.070* | |
H4B | 0.2188 | 0.3841 | 0.3722 | 0.070* | |
C5 | 0.0652 (3) | 0.40013 (13) | 0.29184 (10) | 0.0461 (5) | |
H5 | −0.0478 | 0.3928 | 0.3157 | 0.069* | |
C6 | 0.0974 (3) | 0.49711 (15) | 0.28592 (11) | 0.0550 (6) | |
H6A | −0.0150 | 0.5242 | 0.2728 | 0.082* | |
H6B | 0.1283 | 0.5197 | 0.3272 | 0.082* | |
C7 | 0.2455 (3) | 0.52208 (13) | 0.23995 (10) | 0.0479 (5) | |
H7 | 0.2392 | 0.5843 | 0.2328 | 0.058* | |
C8 | 0.2309 (3) | 0.47658 (12) | 0.17678 (9) | 0.0409 (4) | |
H8 | 0.1261 | 0.5009 | 0.1546 | 0.061* | |
C9 | 0.1986 (3) | 0.37844 (12) | 0.18302 (10) | 0.0400 (4) | |
H9 | 0.3071 | 0.3541 | 0.2029 | 0.060* | |
C10 | 0.0354 (3) | 0.35731 (15) | 0.22679 (10) | 0.0474 (5) | |
C11 | 0.1837 (3) | 0.33797 (15) | 0.11684 (10) | 0.0513 (5) | |
H11A | 0.1757 | 0.2760 | 0.1214 | 0.077* | |
H11B | 0.0718 | 0.3575 | 0.0974 | 0.077* | |
C12 | 0.3409 (3) | 0.35871 (13) | 0.07256 (9) | 0.0436 (5) | |
H12 | 0.3142 | 0.3359 | 0.0305 | 0.052* | |
C13 | 0.3791 (3) | 0.45545 (12) | 0.06769 (9) | 0.0392 (4) | |
C14 | 0.3970 (3) | 0.49118 (12) | 0.13539 (9) | 0.0391 (4) | |
H14 | 0.4968 | 0.4594 | 0.1552 | 0.059* | |
C15 | 0.4659 (4) | 0.58273 (13) | 0.12531 (10) | 0.0529 (6) | |
H15A | 0.5291 | 0.6037 | 0.1624 | 0.079* | |
H15B | 0.3667 | 0.6215 | 0.1155 | 0.079* | |
C16 | 0.5961 (4) | 0.57386 (14) | 0.06910 (10) | 0.0550 (6) | |
H16A | 0.7209 | 0.5795 | 0.0831 | 0.082* | |
H16B | 0.5719 | 0.6184 | 0.0382 | 0.082* | |
C17 | 0.5647 (3) | 0.48375 (13) | 0.03969 (9) | 0.0413 (4) | |
H17 | 0.6573 | 0.4454 | 0.0573 | 0.062* | |
C18 | 0.2224 (3) | 0.49746 (17) | 0.03086 (11) | 0.0549 (5) | |
H18A | 0.2112 | 0.4705 | −0.0097 | 0.082* | |
H18B | 0.2470 | 0.5576 | 0.0254 | 0.082* | |
H18C | 0.1112 | 0.4904 | 0.0539 | 0.082* | |
C19 | −0.1458 (3) | 0.3886 (2) | 0.19834 (13) | 0.0723 (8) | |
H19A | −0.2407 | 0.3823 | 0.2290 | 0.108* | |
H19B | −0.1743 | 0.3548 | 0.1617 | 0.108* | |
H19C | −0.1350 | 0.4479 | 0.1866 | 0.108* | |
C20 | 0.5918 (3) | 0.48459 (14) | −0.03252 (9) | 0.0456 (5) | |
H20 | 0.5073 | 0.5263 | −0.0510 | 0.068* | |
C21 | 0.5581 (4) | 0.39676 (15) | −0.06291 (10) | 0.0577 (6) | |
H21A | 0.5913 | 0.3990 | −0.1067 | 0.087* | |
H21B | 0.4318 | 0.3822 | −0.0593 | 0.087* | |
H21C | 0.6299 | 0.3540 | −0.0419 | 0.087* | |
C22 | 0.7822 (3) | 0.51279 (17) | −0.04687 (11) | 0.0570 (6) | |
H22 | 0.8743 | 0.4743 | −0.0368 | 0.068* | |
C23 | 0.8321 (4) | 0.5855 (2) | −0.07201 (13) | 0.0746 (8) | |
H23A | 0.7453 | 0.6263 | −0.0830 | 0.090* | |
H23B | 0.9545 | 0.5967 | −0.0789 | 0.090* | |
C31 | 0.0556 (5) | 0.24857 (17) | 0.43939 (13) | 0.0670 (7) | |
H31 | −0.0425 | 0.2318 | 0.4641 | 0.080* | |
C71 | 0.5043 (5) | 0.56067 (18) | 0.30160 (12) | 0.0744 (9) | |
H71 | 0.6166 | 0.5469 | 0.3189 | 0.089* | |
C121 | 0.5552 (4) | 0.24346 (14) | 0.07129 (13) | 0.0643 (7) | |
H121 | 0.6602 | 0.2185 | 0.0874 | 0.077* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O3 | 0.0637 (11) | 0.0610 (10) | 0.0607 (10) | −0.0044 (9) | 0.0051 (8) | 0.0080 (8) |
O7 | 0.0585 (9) | 0.0465 (8) | 0.0474 (7) | −0.0070 (7) | −0.0060 (7) | −0.0093 (6) |
O12 | 0.0578 (9) | 0.0372 (7) | 0.0592 (9) | 0.0086 (7) | −0.0053 (8) | −0.0056 (6) |
O31 | 0.0967 (16) | 0.0787 (13) | 0.0640 (11) | 0.0100 (13) | −0.0094 (12) | 0.0008 (10) |
O71 | 0.174 (3) | 0.0777 (15) | 0.1104 (18) | −0.0260 (18) | −0.013 (2) | −0.0489 (14) |
O121 | 0.1141 (18) | 0.0525 (9) | 0.0903 (13) | −0.0053 (12) | 0.0278 (14) | −0.0266 (10) |
C1 | 0.0632 (15) | 0.0586 (13) | 0.0587 (13) | −0.0206 (12) | 0.0003 (13) | −0.0055 (11) |
C2 | 0.0741 (16) | 0.0389 (10) | 0.0664 (14) | −0.0030 (12) | 0.0082 (14) | −0.0032 (10) |
C3 | 0.0539 (13) | 0.0439 (11) | 0.0564 (12) | 0.0026 (10) | 0.0017 (11) | 0.0027 (10) |
C4 | 0.0490 (12) | 0.0402 (10) | 0.0498 (11) | 0.0010 (10) | −0.0033 (10) | −0.0021 (9) |
C5 | 0.0413 (11) | 0.0465 (11) | 0.0503 (11) | 0.0072 (9) | 0.0063 (9) | −0.0004 (9) |
C6 | 0.0629 (14) | 0.0458 (12) | 0.0562 (12) | 0.0169 (11) | 0.0104 (11) | −0.0032 (10) |
C7 | 0.0604 (13) | 0.0336 (9) | 0.0498 (11) | 0.0070 (10) | 0.0033 (10) | −0.0053 (8) |
C8 | 0.0416 (10) | 0.0366 (9) | 0.0445 (10) | 0.0065 (9) | −0.0045 (8) | −0.0032 (8) |
C9 | 0.0372 (10) | 0.0386 (9) | 0.0442 (10) | −0.0010 (8) | −0.0033 (8) | −0.0044 (8) |
C10 | 0.0365 (10) | 0.0548 (11) | 0.0507 (11) | −0.0027 (10) | −0.0042 (9) | −0.0001 (10) |
C11 | 0.0510 (13) | 0.0519 (12) | 0.0511 (11) | −0.0114 (10) | −0.0038 (10) | −0.0127 (10) |
C12 | 0.0463 (11) | 0.0436 (10) | 0.0409 (10) | −0.0034 (9) | −0.0066 (9) | −0.0087 (8) |
C13 | 0.0391 (10) | 0.0395 (10) | 0.0388 (9) | 0.0031 (8) | −0.0067 (8) | −0.0029 (8) |
C14 | 0.0430 (11) | 0.0339 (9) | 0.0406 (9) | 0.0012 (9) | −0.0053 (8) | −0.0040 (7) |
C15 | 0.0692 (15) | 0.0386 (10) | 0.0509 (11) | −0.0075 (11) | 0.0039 (11) | −0.0053 (9) |
C16 | 0.0698 (16) | 0.0460 (11) | 0.0491 (11) | −0.0132 (11) | 0.0005 (12) | −0.0041 (9) |
C17 | 0.0421 (10) | 0.0415 (9) | 0.0402 (9) | 0.0002 (9) | −0.0061 (8) | −0.0009 (8) |
C18 | 0.0469 (12) | 0.0651 (13) | 0.0525 (12) | 0.0089 (12) | −0.0107 (10) | 0.0029 (11) |
C19 | 0.0369 (12) | 0.111 (2) | 0.0691 (16) | 0.0025 (14) | −0.0049 (12) | 0.0091 (16) |
C20 | 0.0471 (11) | 0.0482 (11) | 0.0414 (10) | 0.0068 (10) | −0.0041 (9) | 0.0024 (9) |
C21 | 0.0738 (16) | 0.0580 (13) | 0.0415 (10) | 0.0037 (13) | −0.0028 (11) | −0.0059 (10) |
C22 | 0.0512 (13) | 0.0695 (15) | 0.0504 (12) | 0.0083 (12) | 0.0006 (10) | 0.0026 (11) |
C23 | 0.0645 (17) | 0.0846 (19) | 0.0747 (17) | −0.0059 (16) | 0.0108 (15) | 0.0047 (15) |
C31 | 0.0812 (19) | 0.0569 (14) | 0.0628 (15) | 0.0119 (15) | 0.0100 (15) | 0.0098 (12) |
C71 | 0.098 (2) | 0.0724 (17) | 0.0522 (13) | −0.0291 (17) | −0.0047 (15) | −0.0159 (12) |
C121 | 0.0804 (18) | 0.0373 (11) | 0.0752 (16) | 0.0066 (12) | 0.0256 (15) | 0.0028 (11) |
O12—C121 | 1.329 (3) | C17—C16 | 1.551 (3) |
O12—C12 | 1.462 (3) | C17—H17 | 0.9800 |
O7—C71 | 1.323 (3) | C2—C1 | 1.528 (4) |
O7—C7 | 1.470 (3) | C2—H2A | 0.9700 |
C12—C11 | 1.525 (3) | C2—H2B | 0.9700 |
C12—C13 | 1.534 (3) | C18—H18A | 0.9600 |
C12—H12 | 0.9800 | C18—H18B | 0.9600 |
O3—C31 | 1.328 (3) | C18—H18C | 0.9600 |
O3—C3 | 1.468 (3) | C15—C16 | 1.536 (3) |
C9—C11 | 1.542 (3) | C15—H15A | 0.9700 |
C9—C8 | 1.551 (3) | C15—H15B | 0.9700 |
C9—C10 | 1.553 (3) | C21—C20 | 1.531 (3) |
C9—H9 | 0.9800 | C21—H21A | 0.9600 |
C14—C8 | 1.523 (3) | C21—H21B | 0.9600 |
C14—C15 | 1.527 (3) | C21—H21C | 0.9600 |
C14—C13 | 1.545 (3) | C1—H1A | 0.9700 |
C14—H14 | 0.9800 | C1—H1B | 0.9700 |
C8—C7 | 1.519 (3) | C20—C22 | 1.500 (3) |
C8—H8 | 0.9800 | C20—H20 | 0.9800 |
C3—C2 | 1.507 (3) | C121—O121 | 1.186 (4) |
C3—C4 | 1.512 (3) | C121—H121 | 0.9300 |
C3—H3 | 0.9800 | C22—C23 | 1.304 (4) |
C6—C7 | 1.513 (3) | C22—H22 | 0.9300 |
C6—C5 | 1.532 (3) | C71—O71 | 1.191 (4) |
C6—H6A | 0.9700 | C71—H71 | 0.9300 |
C6—H6B | 0.9700 | C19—H19A | 0.9600 |
C7—H7 | 0.9800 | C19—H19B | 0.9600 |
C13—C18 | 1.539 (3) | C19—H19C | 0.9600 |
C13—C17 | 1.554 (3) | C16—H16A | 0.9700 |
C5—C4 | 1.534 (3) | C16—H16B | 0.9700 |
C5—C10 | 1.547 (3) | C4—H4A | 0.9700 |
C5—H5 | 0.9800 | C4—H4B | 0.9700 |
C11—H11A | 0.9700 | C23—H23A | 0.9300 |
C11—H11B | 0.9700 | C23—H23B | 0.9300 |
C10—C19 | 1.543 (3) | C31—O31 | 1.193 (4) |
C10—C1 | 1.552 (3) | C31—H31 | 0.9300 |
C17—C20 | 1.544 (3) | ||
C121—O12—C12 | 117.6 (2) | C20—C17—H17 | 107.1 |
C71—O7—C7 | 117.4 (2) | C16—C17—H17 | 107.1 |
O12—C12—C11 | 108.40 (17) | C13—C17—H17 | 107.1 |
O12—C12—C13 | 107.53 (16) | C3—C2—C1 | 112.3 (2) |
C11—C12—C13 | 112.84 (18) | C3—C2—H2A | 109.1 |
O12—C12—H12 | 109.3 | C1—C2—H2A | 109.1 |
C11—C12—H12 | 109.3 | C3—C2—H2B | 109.1 |
C13—C12—H12 | 109.3 | C1—C2—H2B | 109.1 |
C31—O3—C3 | 116.7 (2) | H2A—C2—H2B | 107.9 |
C11—C9—C8 | 109.58 (17) | C13—C18—H18A | 109.5 |
C11—C9—C10 | 113.73 (17) | C13—C18—H18B | 109.5 |
C8—C9—C10 | 112.22 (17) | H18A—C18—H18B | 109.5 |
C11—C9—H9 | 107.0 | C13—C18—H18C | 109.5 |
C8—C9—H9 | 107.0 | H18A—C18—H18C | 109.5 |
C10—C9—H9 | 107.0 | H18B—C18—H18C | 109.5 |
C8—C14—C15 | 119.13 (17) | C14—C15—C16 | 103.43 (16) |
C8—C14—C13 | 114.41 (16) | C14—C15—H15A | 111.1 |
C15—C14—C13 | 103.54 (16) | C16—C15—H15A | 111.1 |
C8—C14—H14 | 106.3 | C14—C15—H15B | 111.1 |
C15—C14—H14 | 106.3 | C16—C15—H15B | 111.1 |
C13—C14—H14 | 106.3 | H15A—C15—H15B | 109.0 |
C7—C8—C14 | 112.46 (17) | C20—C21—H21A | 109.5 |
C7—C8—C9 | 113.24 (16) | C20—C21—H21B | 109.5 |
C14—C8—C9 | 108.64 (16) | H21A—C21—H21B | 109.5 |
C7—C8—H8 | 107.4 | C20—C21—H21C | 109.5 |
C14—C8—H8 | 107.4 | H21A—C21—H21C | 109.5 |
C9—C8—H8 | 107.4 | H21B—C21—H21C | 109.5 |
O3—C3—C2 | 106.4 (2) | C2—C1—C10 | 114.3 (2) |
O3—C3—C4 | 111.31 (19) | C2—C1—H1A | 108.7 |
C2—C3—C4 | 110.94 (19) | C10—C1—H1A | 108.7 |
O3—C3—H3 | 109.4 | C2—C1—H1B | 108.7 |
C2—C3—H3 | 109.4 | C10—C1—H1B | 108.7 |
C4—C3—H3 | 109.4 | H1A—C1—H1B | 107.6 |
C7—C6—C5 | 114.67 (17) | C22—C20—C21 | 109.1 (2) |
C7—C6—H6A | 108.6 | C22—C20—C17 | 108.92 (18) |
C5—C6—H6A | 108.6 | C21—C20—C17 | 112.87 (18) |
C7—C6—H6B | 108.6 | C22—C20—H20 | 108.6 |
C5—C6—H6B | 108.6 | C21—C20—H20 | 108.6 |
H6A—C6—H6B | 107.6 | C17—C20—H20 | 108.6 |
O7—C7—C6 | 109.93 (17) | O121—C121—O12 | 127.4 (3) |
O7—C7—C8 | 107.47 (16) | O121—C121—H121 | 116.3 |
C6—C7—C8 | 113.42 (19) | O12—C121—H121 | 116.3 |
O7—C7—H7 | 108.6 | C23—C22—C20 | 126.9 (3) |
C6—C7—H7 | 108.6 | C23—C22—H22 | 116.6 |
C8—C7—H7 | 108.6 | C20—C22—H22 | 116.6 |
C12—C13—C18 | 108.24 (18) | O71—C71—O7 | 125.8 (4) |
C12—C13—C14 | 107.82 (16) | O71—C71—H71 | 117.1 |
C18—C13—C14 | 112.49 (18) | O7—C71—H71 | 117.1 |
C12—C13—C17 | 117.70 (17) | C10—C19—H19A | 109.5 |
C18—C13—C17 | 110.23 (16) | C10—C19—H19B | 109.5 |
C14—C13—C17 | 100.24 (15) | H19A—C19—H19B | 109.5 |
C6—C5—C4 | 110.76 (19) | C10—C19—H19C | 109.5 |
C6—C5—C10 | 111.89 (18) | H19A—C19—H19C | 109.5 |
C4—C5—C10 | 113.41 (18) | H19B—C19—H19C | 109.5 |
C6—C5—H5 | 106.8 | C15—C16—C17 | 107.46 (17) |
C4—C5—H5 | 106.8 | C15—C16—H16A | 110.2 |
C10—C5—H5 | 106.8 | C17—C16—H16A | 110.2 |
C12—C11—C9 | 114.84 (17) | C15—C16—H16B | 110.2 |
C12—C11—H11A | 108.6 | C17—C16—H16B | 110.2 |
C9—C11—H11A | 108.6 | H16A—C16—H16B | 108.5 |
C12—C11—H11B | 108.6 | C3—C4—C5 | 114.38 (19) |
C9—C11—H11B | 108.6 | C3—C4—H4A | 108.7 |
H11A—C11—H11B | 107.5 | C5—C4—H4A | 108.7 |
C19—C10—C5 | 109.6 (2) | C3—C4—H4B | 108.7 |
C19—C10—C1 | 106.2 (2) | C5—C4—H4B | 108.7 |
C5—C10—C1 | 107.43 (19) | H4A—C4—H4B | 107.6 |
C19—C10—C9 | 111.65 (18) | C22—C23—H23A | 120.0 |
C5—C10—C9 | 109.38 (17) | C22—C23—H23B | 120.0 |
C1—C10—C9 | 112.46 (19) | H23A—C23—H23B | 120.0 |
C20—C17—C16 | 111.81 (17) | O31—C31—O3 | 126.3 (3) |
C20—C17—C13 | 119.66 (17) | O31—C31—H31 | 116.8 |
C16—C17—C13 | 103.50 (17) | O3—C31—H31 | 116.8 |
C1—C10—C5—C4 | 51.3 (3) | C13—C17—C20—C21 | −57.8 (3) |
C9—C10—C5—C6 | 55.1 (2) | C17—C20—C22—C23 | −109.7 (3) |
C19—C10—C13—C18 | 3.0 (2) | C13—C17—C20—C22 | −179.10 (18) |
C3—O3—C31—O31 | 3.7 (4) | C13—C17—C20—C21 | −57.8 (3) |
C7—O7—C71—O71 | −0.9 (4) | C16—C17—C20—C21 | −178.9 (2) |
C12—O12—C121—O121 | −0.3 (4) | C21—C20—C22—C23 | 126.7 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
C4—H4A···O7 | 0.97 | 2.35 | 3.029 (3) | 126 |
C12—H12···O121 | 0.98 | 2.37 | 2.750 (3) | 102 |
C14—H14···O12 | 0.98 | 2.53 | 2.929 (2) | 104 |
C17—H17···O12 | 0.98 | 2.43 | 2.890 (3) | 108 |
C31—H31···O31i | 0.93 | 2.49 | 3.396 (4) | 166 |
Symmetry code: (i) x−1/2, −y+1/2, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C26H38O6 |
Mr | 446.56 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 293 |
a, b, c (Å) | 7.365 (3), 15.5549 (12), 21.199 (4) |
V (Å3) | 2428.6 (10) |
Z | 4 |
Radiation type | Cu Kα |
µ (mm−1) | 0.69 |
Crystal size (mm) | 0.37 × 0.24 × 0.24 |
Data collection | |
Diffractometer | Enraf–Nonius MACH-3 diffractometer |
Absorption correction | ψ scan North et al., 1968 |
Tmin, Tmax | 0.744, 0.847 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4523, 2731, 2293 |
Rint | 0.031 |
(sin θ/λ)max (Å−1) | 0.617 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.035, 0.101, 1.03 |
No. of reflections | 2731 |
No. of parameters | 292 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.15, −0.13 |
Computer programs: CAD-4 Software (Enraf-Nonius, 1989), PLATON (Spek,2003), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEPII (Johnson,1976).
C20—C22 | 1.500 (3) | C22—C23 | 1.304 (4) |
C1—C10—C5—C4 | 51.3 (3) | C9—C10—C5—C6 | 55.1 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
C4—H4A···O7 | 0.97 | 2.35 | 3.029 (3) | 126 |
C12—H12···O121 | 0.98 | 2.37 | 2.750 (3) | 102 |
C14—H14···O12 | 0.98 | 2.53 | 2.929 (2) | 104 |
C17—H17···O12 | 0.98 | 2.43 | 2.890 (3) | 108 |
C31—H31···O31i | 0.93 | 2.49 | 3.396 (4) | 166 |
Symmetry code: (i) x−1/2, −y+1/2, −z+1. |
The bile acids, such as cholic acid, have proved particularly useful as `engineering components' for supramolecular chemistry (Davis, 1993). The size, chirality and rigid polycyclic framework of a steroid-based synthetic receptor confers to it a high degree of preorganization. An examination of the structures of the synthetic receptors and their synthetic intermediates, on a crystallographic basis, could help to improve our understanding of molecular-recognition principles. In an attempt to construct a steroid-based synthetic receptor, the title compound, 3β,7α,12α-triformyloxy-24-nor-5β-chol-22-ene, (I), has been synthesized as an intermediate according to ?the method reported by Davis & Walsh (1996)?, although different reactions have been used as described in the experimental section. This cholic acid derivative, without the C(24)OOH group in the 17β side chain, contains three formyloxy groups with a 3β,7α,12α configuration. Cholic and deoxycholic acids provide tunnel-like spaces, reported as a channel-like inclusion ability (Miki et al., 1990; Jones & Nassimbeni, 1990), in which guest molecules can be accommodated. Examination of the crystal structure of (I) shows no guest molecules and a small solvent-accessible volume (i.e. 4 x 15 Å3).
An ORTEPII (Johnson, 1976) plot of (I), with the corresponding atomic numbering scheme and ring labels, is shown in Fig.1. Bond lengths and angles are within the expected ranges (Allen et al., 1987), the mean O—Csp3, O—Csp2 and O═Csp2 distances being 1.467 (3), 1.331 (3) and 1.189 (2) Å in the three formyloxy groups, and the mean Csp3—Csp2 and Csp2═Csp2 distances being 1.503 (3) and 1.304 (4) Å in the 17β-group. The distance between the terminal atoms, O31—C23, is 13.275 (4) Å and the C19—C10—C13—C18 pseudo-torsion angle is 3.0 (2)°. The A/B ring junction is 5β,10β cis [C1—C10—C5—C4 = 51.3 (3)° and C9—C10—C5—C6 = 55.1 (2)°]. The bowing angle between ring A and the least-squares plane that includes the atoms of B, C and D rings is 63.16 (5)°. Rings A, B and C have slightly flattened chair conformations, with average torsion angles of 52.6 (7), 52.0 (14) and 55.0 (16)°, respectively, as shown by the values [177.0 (3), 8.0 (2) and 6.6 (2)° for A, B and C] of the θ puckering parameter (Cremer & Pople, 1975; Boeyens, 1978). The five-membered ring D assumes a 13β,14α half-chair conformation [puckering parameters, calculated using the atom sequence C13···C17: q2 = 0.461 (2) Å and ϕ2 = 195.4 (3)°; pseudo-rotation (Altona et al., 1968) and asymmetry parameters: Δ = −3.8 (2), ϕm = 46.8 (1), ΔCs(13) = 16.0 (2), ΔCs(14) = 19.4 (2) and ΔC2(13,14) = 2.7 (2)°]. This unusal ring conformation is different from that observed in cholic acid (Jones & Nassimbeni, 1990). The three 3β,7α,12α-ring substituents are axial (Luger & Bulow, 1983), with angles of 6.3 (2), 9.9 (1) and 4.6 (1)°, respectively. The angle between the planes defined by the 3β-group and the A ring is 80.5 (2)°, and those between the planes of the 7α-,12α-groups and the mean plane of rings B, C and D are 85.6 (3) and 89.6 (2)°, respectively. The 17β-chain is equatorial. The orientation of the C5–C17 reference plane relative to C17/C20/C21 and C2/C22/C23 least-squares planes is 19.54 (19) and 77.30 (19)° respectively, with the angle between these two planes being 85.0 (2)°. Comparing with the structure of cholic acid (Miki et al., 1990; Jones & Nassimbeni, 1990), the absence of the COOH group in the side chain attached to C17 may be responsible for the unusual values of the C17—C20—C22—C23 and C21—C20—C22—C23 torsion angles [−109.7 (3) 126.7 (3)°], corresponding to -ac and +ac descriptors, respectively, instead of -ap and +sc.
The crystal structure contains no classical hydrogen bonds and thus cohesion of the structure is mainly achieved by van der Waals interactions and C–H···O weak interactions. Four intramolecular C–H···O short contacts are present; one [C4–H4A···O7 at 3.029 (3) Å with bent angle 126°] is probably a destabilizing interaction; the other three may be qualified as weak hydrogen bonds with distances and angles in the ranges 2.750 (4)–2.929 (3) Å and 102–108°, respectively. An intermolecular C31–H31···O31(i) interaction [3.396 (4) Å and 166°; symmetry code: (i) −1/2 + x, 1/2 − y, 1 − z] is also present, linking the molecules head-to-head in dimers.