Toluene → Cholest-4-en-3-one

Participants

Reaction Steps

111 g. of 3β-hydroxy-5-cholestene is heated in 2.2 l. of toluene and 111 ml. of cyclohexane to boiling. A solution of 55.5 g. of aluminum isopropylate in 666 ml. of toluene is added dropwise thereto. The mixture is then further heated for 90 minutes with gradual distillation. The cooled reaction solution is diluted with ether, washed with dilute sulfuric acid and water, and concentrated. The residue is distilled with steam and the crude product, obtained after extraction with methylene chloride, is chromatographed on silica gel. After recrystallization from methanol, 70 g. of 4-cholesten-3-one is obtained, m.p. 79° - 80.5° C.

Provenance & Evidence