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

The crystal structure of 3β-acetoxy-12-keto-(25R)-5β-spirostanyl acetate has been determined by X-ray diffraction methods. The title compound (C'29 H44O5) crystallizes in monoclinic space group P21 with cell parameters, α = 10.547(4), b = 7.124(8), c = 18.110(10) Å, β = 98.23(4)° 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 interaction. © 2005 IACS.