(4aR,4bS,6aS,7S,9aS,9bS,11aS)-4a,6a-diMethyl-2-oxohexadecahydro-1H-indeno[5,4-f]quinoline-7-carboxylic acid

3-Oxo-4-aza-5b-androstan-17b-carboxylic Acid is an intermediate in the synthesis of 5b-Finasteride (F342030). 5b-Finasteride is an azasteroid and 5b-isomeric impurity of Finasteride (F342000). Finasteride is an inhibitor of 5a-reductase, the enzyme which converts testosterone to the more potent androgen, 5a-dihydrotestosterone and it an antialopecia agent.