反应详情

A solution of N-(tert-butoxycarbonyl)-L-serine methyl ester (25.0 g, 114 mmol) in DCM (570 mL) was cooled to −50° C. Pyridine (23.0 mL, 285 mmol) was added. CBZ-Cl (18.9 mL, 125 mmol) was added dropwise over 1 hour. The reaction mixture was warmed to ambient temperature and stirred overnight. The reaction mixture was then diluted with DCM, washed with 10% citric acid and brine, dried and concentrated under reduced pressure. The residue was purified by flash chromatography on silica gel (5:1 hexanes/EtOAc) to give (S)-methyl 3-(benzyloxycarbonyloxy)-2-(tert-butoxycarbonylamino)propanoate (36.0 g, 89%).

1. washwashed with 10% citric acid and brine
2. customdried
3. concentrationconcentrated under reduced pressure
4. customThe residue was purified by flash chromatography on silica gel (5:1 hexanes/EtOAc)