Water → Hexamethyldisiloxane

Participants

Reaction Steps

To a solution of 25-hydroxycholecalciferol (5.0 g.) in pyridine (25 ml.) at -15°, under an atmosphere of argon, is added 4-(N,N-dimethylamino)-pyridine (50 mg) followed by benzoyl chloride (2.10 ml.). The solution is warmed to 0° and kept at this temperature for 1.5 hours. After cooling to -15°, trimethylchlorosilane (1.75 ml.) is added and then the mixture is heated to room temperature for 10 minutes, before pouring into water. The mixture is extracted with hexane (500 ml.) and the extracts washed with brine, dilute hydrochloric acid, brine, sodium bicarbonate solution, brine and then dried over sodium sulfate. Evaporation of the solution yields 25-hydroxycholecalciferol, 3-benzoate, trimethylsilylether as an oil.

Provenance & Evidence