反应详情

Carbon tetrabromide (1.64 g, 4.95 mmol) and triphenylphosphine (1.30 g, 4.95 mmol) were sequentially added to a solution of (3S)-3-(2-hydroxyethyl)-4-methyl-5-oxo-1-[(1R)-1-phenylethyl]pyrrolidine-3-carboxylic acid tert-butyl ester (1.56 g, 4.50 mmol) in dichloromethane (20 mL) in a nitrogen atmosphere at 0° C. After heating to room temperature, the reaction solution was stirred for 10 minutes and concentrated to about 5 mL. The residue was purified by silica gel column chromatography (dichloromethane→hexane:ethyl acetate=4:1→2:1→1.5:1) to give 1.30 g (70%) of the diastereomer mixture title compound as a white solid.

1. concentrationconcentrated to about 5 mL
2. customThe residue was purified by silica gel column chromatography (dichloromethane→hexane:ethyl acetate=4:1→2:1→1.5:1)