title: 3,17-Dioxoandrost-4-en-4-yl acetate.
abstract: The title compound, C(21)H(28)O(4), has a 4-acetoxy substituent positioned on the steroid alpha face. The six-membered ring A assumes a conformation intermediate between 1alpha,2beta-half chair and 1alpha-sofa. A long Csp(3)-Csp(3) bond is observed in ring B and reproduced in quantum-mechanical ab initio calculations of the isolated molecule using a molecular-orbital Hartree-Fock method. Cohesion of the crystal can be attributed to van der Waals interactions and weak C-H...O hydrogen bonds.
authors.affiliation: CEMDRX, Department of Physics, University of Coimbra, Coimbra, Portugal.
authors.forename: L C R
authors.initials: LC
authors.lastname: Andrade
authors.forename: J A
authors.initials: JA
authors.lastname: Paixão
authors.forename: M J M
authors.initials: MJ
authors.lastname: de Almeida
authors.forename: F M
authors.initials: FM
authors.lastname: Fernandes Roleira
authors.forename: E J
authors.initials: EJ
authors.lastname: Tavares da Silva
mesh_terms: D000085:Acetates / Q000737:chemistry*; D000735:Androstenedione / Q000031:analogs & derivatives*; D000736:Androstenes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008968:Molecular Conformation
chemical_list: C522853:3,17-dioxoandrost-4-en-4-yl acetate; D000085:Acetates; D000736:Androstenes; D000735:Androstenedione