反应详情

Carbon tetrabromide (3.24 g, 9.77 mmol) and triphenylphosphine (2.57 g, 9.80 mmol) were added to a solution of (3S)-3-(3-hydroxy-2-methylene-1-propyl)-5-oxo-1-[(1R)-1-phenylethyl]pyrrolidine-3-carboxylic acid tert-butyl ester in dichloromethane (113 ml) under ice water-cooling in a nitrogen atmosphere. The mixture was stirred under ice water-cooling for 15 minutes and then concentrated under reduced pressure to remove the solvent. The resulting residue was purified by silica gel column chromatography (hexane:ethyl acetate=100:0→95:5→90:10→80:20→75:25→66:34) to give 3.22 g of the title compound as white crystals.

1. temperaturecooling in a nitrogen atmosphere
2. temperaturecooling for 15 minutes
3. concentrationconcentrated under reduced pressure
4. customto remove the solvent
5. customThe resulting residue was purified by silica gel column chromatography (hexane:ethyl acetate=100:0→95:5→90:10→80:20→75:25→66:34)