Fourteen new 4-aza-Δ5-androstene-17-oximido-ether and oximido-ester compounds were synthesized using androst-4-ene-3,17-dione (AD) as starting material. The structures of all the intermediates and final products were identified by MS and NMR. The product compounds were evaluated for their inhibition rate to rat liver microsomal 5α-reductase and the results show that all of the compounds exhibited 5α-reductase inhibition activity to some degree. Among them, compounds 5a, 5c and 5d showed the highest biological activity, which appeared to be at the same level of the contrasting drug Espristeride.

Key words: 4-aza-17-substituted steroid, 5α-reductase, inhibitor, synthesis