反应详情

To ethyl 3-(benzyl(cyclopentyl)amino)-2-hydroxy-2-methylpropanoate (4.2 g, 14 mmol) in 50 ml of dichlormethane at −78° C., was added DAST (2.7 ml, 21 mmol) dropwise. The reaction mixture was gradually warmed up to room temperature and stirred for 2 h. It was then diluted to dichloromethane, washed by NaHCO3, brine and water. Organic extract dried and concentrated to a residue, which was purified on silica gel column chromatographically (Hex/EtOAc=40:1 to 20:1) to give 3.5 g product (83%) as light yellow liquid. [M+H] calc'd for C18H26FNO2, 308; found 308.

1. washwashed by NaHCO3, brine and water
2. extractionOrganic extract
3. customdried
4. concentrationconcentrated to a residue, which
5. customwas purified on silica gel column chromatographically (Hex/EtOAc=40:1 to 20:1)