Dutasteride164656-23-9100 % similar Finasteride98319-26-762 % similar 3-Oxo-4-aza-5α-androst-1-ene-17β-carboxylic acid104239-97-657 % similar 3-Oxo-4-aza-5α-androstane-17β-carboxylic acid103335-55-333 % similar