反应详情

Carbon tetrabromide (1.88 g, 5.68 mmol) and triphenylphosphine (1.49 g, 5.68 mmol) were sequentially added to a solution of (3S)-4-fluoro-3-(2-hydroxyethyl)-5-oxo-1-[(1R)-1-phenylethyl]pyrrolidine-3-carboxylic acid tert-butyl ester (1.66 g, 4.74 mmol) in dichloromethane (20 mL) in a nitrogen atmosphere at 0° C. After heating to room temperature, the reaction solution was stirred for one hour and concentrated to about 5 mL. The residue was purified by silica gel column chromatography (dichloromethane→hexane:ethyl acetate=2:1) to give 2.17 g (91%) of the 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=2:1)