17alpha,21-Dihydroxy-16beta-methylpregna-1,4-diene-3,11,20-trione (meprednisone).

The title compound, C(22)H(28)O(5), is a commercial therapeutic agent of the steroid class. Both independent molecules in the asymmetric unit have six-membered A rings that are planar, while the B and C rings adopt normal chair conformations. The five-membered D ring is in a 13beta,14alpha-half-chair conformation, and the B/C and C/D ring junctions are in trans positions. Cohesion in the crystal is provided by O-H.O hydrogen bonds, which generate chains of molecules that are organized in a plane that lies along the crystallographic b axis.