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The title compound, C31H48O7·0.04CH3COOH, is a polyoxy­genated steroid obtained by selective chemical oxidation of 7-de­hydro­cholesteryl acetate. The asymmetric unit comprises three mol­ecules of the steroid (Z′ = 3) and a mol­ecule of acetic acid which has occupancy factor 0.131 (5). The geometric parameters of the independent mol­ecules do not reveal significant differences. In one mol­ecule, the terminal isopropyl group is disordered over two sets of sites with occupancy ratio 0.869 (5):0.131 (5). The three mol­ecules reveal different hydrogen-bonding patterns. Each of them is involved in an intra­molecular S(6) hydrogen-bonding motif, involving hy­droxy groups as donor and acceptor. In the crystal, two independent mol­ecules form dimers through hydrogen bonding between an OH donor and an acetate carbonyl acceptor, giving rise to R22(16) ring patterns. A single hydrogen bond between the OH group and a ketone carbonyl group is observed between two symmetry-independent mol­ecules.

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The title compound, C31H48O7, a polyoxygenated steroid, was obtained by chemical oxidation of 7-de­hydro­cholesteryl acetate. The mol­ecular geometry features trans A/B and C/D junctions at the steroid core with the acetyl groups in the equatorial position and a fully extended conformation for the alkyl side chain. A chair conformation is observed for rings A and C while ring B adopts a half-chair conformation. The five-membered ring D has an envelope conformation, with the C atom bearing the methyl group at the flap. The terminal isopropyl group and one acetyl group are disordered over two sets of sites with 0.774 (8):0.226 (8) and 0.843 (7):0.157 (7) ratios, respectively. An intra­molecular S(6) O—H...O hydrogen-bonding motif involving a hy­droxy donor and acceptor is observed. In the crystal, chains of mol­ecules running along the b axis are formed via O—H...O hydrogen bonds between hy­droxy donors and carbonyl acceptors of the ordered acetyl group, giving rise to a C(14) motif. The chains are wrapped around the 21 screw axes.

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The title compound, C20H18O6, prepared from D-mannitol by a two-step procedure, is a functionalized fused bis-tetra­hydro­furan. In the central fragment, consisting of two fused tetra­hydro­furan rings, one O atom and its two adjacent C atoms, a methyl­ene and a bridgehead C atom, are disordered over two sets of sites with an occupancy ratio of 0.735 (9):0.265 (9). In the major component, the ring containing the disordered O atom is a half-chair conformation with twisted methylene and benzoate-substituted C atoms, whereas the other ring has a half-chair or T-form conformation. In the minor component, the ring with the disordered O atom has an envelope conformation, with the O atom as the flap, and the other ring has a half-chair conformation, with the O atom and the other bridgehead CH atom being twisted. The two aromatic rings are inclined to one another by 20.00 (12)°. In the crystal, adjacent molecules are linked via C—H...π interactions, forming chains propagating along [010].
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