Methyl 3-[(chloromethoxy)carbonyloxy]-7-hydroxycholan-24-oate

Abstract

The title compound, C27H43ClO6, is a derivative of ursodeoxycholic acid, in which the OH group at the 3-position is substituted by a chloromethoxycarbonyloxy substituent and the carboxylic acid group at the 24-position is methylated. The A and B rings are cis-fused, while all other rings are trans-fused. In the crystal, two adjacent molecules located along the b-axis direction are interlocked head-to-tail due to weak C—H...O hydrogen bonds. Therefore each molecule is linked to four neighbouring molecules by four C—H...O hydrogen bonds, with the OH group at the 7-position and the carbonyl O atom of the ester group acting as the acceptor sites.