Hydrochloric Acid → 16beta-Methly-5-androsten-17-one

Participants

Reaction Steps

The crude methyl enamide acetate (3, 1.94 g) was refluxed in 100 ml each of THF and water with 10 ml of concentrated HCl for 31/2 hours. Following the usual work-up the crude hydroxy methyl ketones (5 and 6) were converted to the 3-acetates. Silica gel thin layer chromotography using isooctane-ethyl acetate (21:4) roughly showed a 3:1 mixture of polar (Rf 0.17) and mobile (Rf 0.21) products, representing a mixture of the 16α-methyl and 16β-methyl-17-ones, respectively. Crystallization of the original 3-hydroxy mixture gave 425 mg of pure 16β-methyl-5-androsten-17-one (6), mp 168°-170°. The mother liquor residue (660 mg) represented a mixture of 16α and 16β-methyl-3-hydroxy-17-ones (5 and 6).

Provenance & Evidence