反应详情

Compound II (7.4 g) and cyclopentanone (4.1 g, 49 mmol) were dissolved in 80 mL DCM. After the addition of sodium acetate (4.0 g, 4 mmol) and sodium triacetoxyborohydride (15.0 g, 71 mmol) at 0° C., the mixture was stirred for 12 hr at rt and then 50 mL saturated sodium bicarbonate solution were added. The aqueous phase was extracted with dichloromethane. The combined organic phases were washed with water, dried over MgSO4 and evaporated down to give (R)-methyl 2-(cyclopentylamino)butanoate as a light yellow oil (compound III, 8.6 g, 95% yield).

1. extractionThe aqueous phase was extracted with dichloromethane
2. washThe combined organic phases were washed with water
3. dry with materialdried over MgSO4
4. customevaporated down