p-Toluenesulfonic acid → HCID 57225501, compound

Participants

Reaction Steps

To a solution of (1R,2S)-1,2-dihydroxy-1-(4,5-diphenyloxazol-2-yl)cyclohexane (18 g) in methylene chloride (200 ml) were added orthoacetic acid trimethyl ester (9.7 ml) and p-toluenesulfonic acid (20 mg) at room temperature under N2. After stirring the mixture for 30 minutes, the solvent was evaporated in vacuo. The residue was diluted with methylene chloride (200 ml) and acetyl bromide (5.8 ml) was added to the solution at 0° C. under N2. After stirring the mixture for 2 hours at room temperature, the solvent was evaporated in vacuo, the residue was diluted with MeOH (200 ml), and potassium carbonate (12 g) was added to the solution at room temperature. The mixture was stirred for 2 hours at the same temperature and partitioned between EtOAc and water. The organic layer was washed with 1N-hydrochloric acid, water, saturated sodium hydrogencarbonate and brine. The dried solvent was evaporated in vacuo and the residue was purified by chromatography on silica gel to give (1R,2S)-1-(4,5-diphenyloxazol-2-yl)-1,2-epoxycyclohexane (14.1 g).

Provenance & Evidence