Redetermination of 5α-androstane-3,17-dione.

The structure of the title compound, C(19)H(28)O(2), has been redermined at 295 (2) K, with much improved precision. The structure and mol-ecular packing of the title compound was first reported by Coiro et al. [Acta Cryst. (1973). B29, 1404-1409] by means of potential-energy calculations. The cell parameters in this study differ considerably in space group C2. It is a derivative of testosterone and consists of a cyclo-penta-none ring (A) fused to to successive cyclo-hexane (B and C) and cyclo-hexa-none (D) rings. The three cyclo-hexa-none rings are in slightly distorted boat configurations and the cyclo-penta-none ring is a distorted half-chair. The crystal packing is stabilized by weak inter-molecular C-H⋯O inter-actions involving O atoms from each of the cyclo-hexa-none and cyclo-penta-none rings and H atoms from each of their respective rings.