Crystal structure of an epoxysterol: 9alpha,11alpha-epoxy-5alpha-cholest-7-ene-3beta,5,6alpha-triol 3,6-diacetate

The title compound, C31H48O6, is a polyoxygenated epoxy steroid obtained by a multi-step synthesis involving oxidation of 7-dehydrocholesterol. It crystallizes in the P212121 space group; however, the absolute structure of the molecule in the crystal could not be determined by resonant scattering. The configuration at the C5 and C6 positions is in both cases of the alpha-type, as is that of the C atoms of the epoxy ring. Molecules in the crystal form chains parallel to the b axis by hydrogen bonding between O—H donors and carbonyl O-atom acceptors. Some atoms of the alkyl chain are disordered over two orientations, with a refined occupancy ratio of 0.511 (10):0.489 (10).