Abstract
As the key intermediates leading to the titled compounds 17β-(5-isoxazolyl)androst-14-ene (IIb) and 17β-(3-pyrazolyl) androst-14-ene (VIa) were prepared from 20-ethoxy-21-formyl-17β-pregna-14, 20-diene (Ib) with hydroxylamine and hydrazine hydrate, respectively. Epoxidation of IIb with monoperphthalic acid did take place from the α-side of the Δ14-double bond to yield the 14α, 15α-oxido compounds (III). Reaction with N-bromoacetamide followed by treatment with alumina resulted in formation of the epimeric β-epoxides (V). Similar elaborations with the 17β-(3-pyrazolyl)-Δ14-steroid gave the epimeric 14, 15-epoxides (VII, IX) with success, when VIa was previously converted into the N-acetate (VIb).
