New approach to 3-oxo-4-aza-5α-androst-1-ene-17β-(N-tert-butylcarboxamide)

We describe the synthesis of 3-oxo-4-aza-5α-androst-1-ene-17β-(N-tert-butylcarboxamide) (finasteride) from 4-androstene-3,17-dione (AD) in seven steps in an overall yield of 18.6% via oxidation, ammoniumation, dehydration, and dehydrogenation.