POLYMORPHISM IN DETHOXYPRONE, A STEROIDAL ANESTHETIC .1. STRUCTURE OFBETA-ETHOXY-3-ALPHA-HYDROXY-5-ALPHA-PREGNAN-20-ONE (DETHOXYPRONE FORM-I)

C25H43NO3, M(r) = 405, monoclinic, P2(1), a = 8.654 (2), b = 6.428 (1) , c = 21.032 (3) angstrom, beta = 95.7 (2)degrees, V = 1164 (2) angstr om3, Z = 2, D(x) = 1.16 g cm-3, lambda(Cu Kalpha) = 1.5418 angstrom, m u = 5.05 cm-1, F(000) = 448, room temperature, R = 0.042 for 2185 obse rved reflections. All rings of the steroid skeleton are trans connecte d. Rings A, B and C are all in the chair conformation. Ring D is in a half-chair conformation. The molecules are hydrogen bonded in a head-t o-head fashion through H(O3) and O(2) in a staggered arrangement linki ng molecules stacked along b.