反应详情

To a solution of ethyl(4S)-4-{[(benzyloxy)carbonyl]amino}-3-(tert-butyldimethylsilyloxy)hexanoate (64.0 g) in methanol (500 mL) was added 10% palladium carbon (containing 50% water, 6.5 g), and the mixture was stirred at room temperature for 3.5 hr under a hydrogen atmosphere and filtered. Sodium methoxide (13.6 g) was added to the filtrate, and the mixture was stirred at room temperature for 2 hr. Water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The extract was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: hexane/ethyl acetate=20/1→1/4) to give the title compound (yield: 21.6 g, 59%) and (4S,5S)-4-(tert-butyldimethylsilyloxy)-5-ethylpyrrolidin-2-one (yield: 4.64 g, 13%) as a colorless solid and a colorless oil, respectively.

1. filtrationfiltered
2. additionSodium methoxide (13.6 g) was added to the filtrate
3. stirringthe mixture was stirred at room temperature for 2 hr
4. additionWater was added to the reaction mixture
5. extractionthe mixture was extracted with ethyl acetate
6. dry with materialThe extract was dried over anhydrous magnesium sulfate
7. concentrationconcentrated under reduced pressure
8. customThe residue was purified by silica gel column chromatography (eluent: hexane/ethyl acetate=20/1→1/4)