title: 17alpha,21-Dihydroxy-16beta-methylpregna-1,4-diene-3,11,20-trione (meprednisone).
abstract: 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.
authors.affiliation: Escuela de Ciencia y Tecnología, Universidad Nacional de General San Martín, Calle 91 3391, 1653 Villa Ballester, Buenos Aires, Argentina. fernande@tandar.cnea.gov.ar
authors.forename: Daniel
authors.initials: D
authors.lastname: Fernández
authors.forename: Daniel
authors.initials: D
authors.lastname: Vega
authors.forename: Javier A
authors.initials: JA
authors.lastname: Ellena
mesh_terms: D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D011241:Prednisone / Q000031:analogs & derivatives* / Q000737:chemistry*
chemical_list: C008352:meprednisone; D011241:Prednisone