Ammonium Chloride → HCID 86751632, compound

Participants

Reaction Steps

A solution of 3.21 g (9.8 mmol) of tert-butyl (4S,5R)-4-(cyclohexylmethyl)-5-formyl-2,2-dimethyl-3-oxazolidinecarboxylate (WO 87/05302) in 25 ml of tetrahydrofuran is added dropwise at about 15° to a solution of the Grignard compound prepared from 3.94 ml (49 mmol) of cyclopropyl bromide and 1.2 g (0.049 gram atom) of magnesium shavings in 22 ml of tetrahydrofuran and the reaction mixture is subsequently stirred at room temperature under argon for 16 hours. Thereafter, the reaction mixture is poured into 40 ml of an ice-cold, saturated ammonium chloride solution and extracted twice with 50 ml of ethyl acetate each time. The ethyl acetate extracts are washed with 40 ml of ice-cold, saturated ammonium chloride solution, combined, dried over sodium sulphate and evaporated. For purification, the residue (4.33 g) is chromatographed over a column of 110 g of silica gel, prepared with toluene and 1% triethylamine, using a 95:5 mixture of toluene and ethyl acetate as the eluent. There are obtained 1.9 g of tert-butyl (4S,5R)-4-(cyclohexylmethyl)-5-[(S)-cyclopropylhydroxymethyl]-2,2-dimethyl-3-oxazolidinecarboxylate, MS: 368 (M+H)+, and 0.5 g of tert-butyl (4S,5R)-4-(cyclohexylmethyl)-5-[(R)-cyclopropylhydroxymethyl]-2,2-dimethyl-3-oxazolidinecarboxylate, MS: 368 (M+H)+, both as a colourless oil.

Provenance & Evidence