INVESTIGATIONS OF DEHYDROEPIANDROSTERONE .1. CRYSTAL-STRUCTURE OF SUBLIMED DHEA

The crystal structure of an orthorhombic polymorph of the title compou nd, crystallized by sublimation, has been determined. Dehydroepiandros terone, C19H28O2, space group P2(1)2(1)2(1) with a = 6.6408(4) b = 11. 4423(11) c = 22.085(2)Angstrom, V = 1678.2(4)Angstrom(3), Z = 4. The s tructure was refined to R = 0.051 for 2645 observed reflections. The c onformation of the molecule is similar to that found in other polymorp hs and solvates, with a chair A ring, an 8 beta, 9 alpha half-chair B ring, a chair C ring, and a 14 alpha envelope D ring. Molecules are li nked in chains by OH ... O hydrogen bonds involving the carbonyl oxyge n atom. The O ... O distance is 2.855(3)Angstrom, and the angle about H is 171(2)degrees.