反应详情

8.8 g benzyl prolinate hydrochloride, 9.78 g dicyclohexylcarbodiimide and 6.12 g diisopropylethylamine were reacted together in 50 mL dichloromethane at 0°. 5.51 g 2-oxopentanoic acid in 10 mL dichloromethane was added dropwise at 0°. The pH of the reaction was adjusted to between 8 and 9 with diisopropylethylamine. The reaction mixture was stirred for four hours at 0°, then room temperature overnight. The next day, the reaction mixture was filtered, concentrated to dryness, and partitioned between ethyl acetate and water. The organic layer was washed with 5% sodium bisulfate, 5% sodium bicarbonate, and saturated sodium chloride solutions, and dried with magnesium sulfate. The organic layer was concentrated to give a yellow oil. The oil was then passed through a silica gel column and eluted with ethyl acetate/hexane (4:6) and ethyl acetate/hexane (1:1). Benzyl N-(2-oxopentanoyl)prolinate, [α]D25 -56.9, was isolated.

1. customroom temperature overnight
2. filtrationThe next day, the reaction mixture was filtered
3. concentrationconcentrated to dryness
4. custompartitioned between ethyl acetate and water
5. washThe organic layer was washed with 5% sodium bisulfate, 5% sodium bicarbonate, and saturated sodium chloride solutions
6. dry with materialdried with magnesium sulfate
7. concentrationThe organic layer was concentrated
8. customto give a yellow oil
9. washeluted with ethyl acetate/hexane (4:6) and ethyl acetate/hexane (1:1)