反应详情

温度

0 °C

To a solution of N-(benzyloxy)carbonyl-D-glutamic acid 5-tert-butyl ester (35 g, 102 mol) in THF (500 ml) was added at −30° C. triethylamine (17 ml, 122 mmol), followed by addition of ethyl chloroformate (12 ml, 122 mmol) and the mixture was stirred at the same temperature. Then to the mixture was added at −30° C. a solution of sodium borohydride (11.6 g, 306 mmol) in water (51 ml) and the mixture was stirred for 30 minutes. Then the solution was raised to 0° C. and stirred for 30 minutes. To the reaction mixture was added water and the solution was extracted three times with ethyl acetate and the organic layer was washed with a saturated aqueous sodium chloride solution, dried over magnesium sulfate and the organic solvent was removed under reduced pressure. The residue was purified by silica gel (210 g) chromatography (Hexane/ethyl acetate: 3/2→1/1) to give tert-butyl (4R)-4-{[(benzyloxy)carbonyl]amino}-5-hydroxypentanoate (16.5 g, 50%).

1. stirringthe mixture was stirred for 30 minutes
2. stirringstirred for 30 minutes
3. extractionthe solution was extracted three times with ethyl acetate
4. washthe organic layer was washed with a saturated aqueous sodium chloride solution
5. dry with materialdried over magnesium sulfate
6. customthe organic solvent was removed under reduced pressure
7. customThe residue was purified by silica gel (210 g) chromatography (Hexane/ethyl acetate: 3/2→1/1)