(25R)-16β-Acetoxy-3β-bromo-23′,26-epoxy-23′,25-dimethyl-5α-cholest-23,23′-en-6-one dichloromethane monosolvate

Abstract

The crystal structure of the title compound, C31H45BrO5·CH2Cl2, prepared in six steps from diosgenin, confirmed that the configurations of the stereogenic centers, positions 20S and 25R, remain unchanged during the reaction. The six-membered A, B and C rings have chair conformations. The five-membered ring D has an envelope conformation (with the methyl-substituted C atom fused to ring C as the flap) and the six-membered dihydropyran ring E adopts a twist-boat conformation. In the crystal, molecules are linked via C—H...O and C—H...Cl hydrogen bonds, the latter involving the dichloromethane solvent molecule, forming a three-dimensional supramolecular network.