Hydrochloric Acid → Pregnane-3alpha,20alpha-diol

Participants

Reaction Steps

To a stirred solution of 3α-acetoxy-5α-pregn-16-en 20-one (970 mg, 358.5 g/m, 2.7 mmol) in 130 mL of dry isopropanol was added sodium metal (8.0 g, 23 g/m, 348 mmol) slowly in small portions over 1 hr. After refluxing for 1 hour an additional amount of sodium (3.5 g) was added and reflux continued for 1 hour. The reaction mixture was acidified with 10% HCl and extracted with chloroform. The organic phase was dried over magnesium sulfate and concentrated to give the crude product. Recrystallization from acetone with cooling in the freezer gave 80 mg of a mixture (93:7) of 20α and 20β respectively. Additional recrystallization from methanol resulted in the pure title product.

Provenance & Evidence