6β-Azido-7α-hydroxy-17-oxo-5α-androstan-3β-yl acetate

Abstract

In the title compound, C21H31N3O4, a potential inhibitor of aromatase, all rings are fused trans. Rings A, B and C have chair conformations which are slightly flattened. Ring D has a 14alpha-envelope conformation. The steroid nucleus has a small twist, as shown by the C19-C10...C13-C18 torsion angle of 6.6 (2) degrees. Ab initio calculations of the equilibrium geometry of the molecule reproduce this small twist, which appears to be due to the steric effect of the 6beta-azide substituent rather than to packing effects.