Structure analysis of 3 beta-acetoxy-12-keto-(25R)-5 beta-spirostanyl acetate

The crystal structure of 3 beta-acetoxy-12-keto-(25R)-5 beta -spirostanyl acetate has been determined by X-ray diffraction methods. The title compound (C29H44O5) crystallizes in monoclinic space group P2(1), with cell parameters, a = 10.547(4), b = 7.124(8), c = 18.110(10) angstrom, beta + 98.23(4)degrees and Z = 2. The reliability index of the structure is 0.068 for 1645 observed reflections. Four six-membered rings A, B, C and F exist in chair conformation. The five-membered ring D occupies a distorted half-chair conformation while the ring E adopts a half chair conformation. The crystal structure is stabilized by few C-H...O intra- and intermolecular interactions.