Lithium → 1-Hydroxycholest-5-ene

Participants

Reaction Steps

A three-necked standard taper round-bottom flask equipped with a mechanical stirrer, dry ice condenser, a nitrogen inlet and an ammonia inlet was thoroughly dried, flushed with nitrogen, cooled in a dry ice-acetone bath and charged with ammonia (60 ml). Lithium (0.4 g, 0.06 mole) was added portionwise under an atmosphere of nitrogen with stirring. A solution of 4,6-cholestadien-1α,3β-diol (4, 0.518 g, 1.29 mmoles) in freshly distilled tetrahydrofuran (60 ml) was added and, after removal of the cooling bath, the reaction mixture was stirred for 3 hours. Ammonium chloride (ca 0.5 g) was added and after stirring for 1 hour, saturated ammonium chloride solution was added. The ammonia was allowed to evaporate. Water was added o the residue and the solution was extracted with ether. The combined organic extracts were washed with water, dried over anhydrous sodium sulfate, filtered and the filtrate was evaporated under vacuum. Filtration of the residual solid (0.509 g) dissolved in low boiling petroleum ether through a column of silica gel gave 0.3 g (60%) of carbinol 5.

Provenance & Evidence