反应详情

温度

70 °C

Dissolved in 40 ml of dimethylformamide were 8.54 g of L-phenylalanine benzyl ester p-toluenesulfonate and 3.40 g of 2-bromo-γ-butyrolactone. After a dropwise addition of 4.04 g of triethylamine, the resultant mixture was heated and stirred at 70° C. for 18 hours. The reaction mixture was poured into chilled water, followed by extraction with ethyl acetate. The extract was washed successively with water, a 2% aqueous solution of sodium hydrogencarbonate, and water. After drying the extract over anhydrous sodium sulfate, it was distilled under reduced pressure. The residue was isolated and purified by chromatography on a silica gel column (toluene:ethyl acetate=20:1-5:1). From initial fractions of the column effluent, 1.75 g of N-(2-oxo-3-tetrahydrofuranyl)-L-phenylalanine benzyl ester (Isomer A) was obtained as a colorless oily substance.

1. additionThe reaction mixture was poured
2. extractionfollowed by extraction with ethyl acetate
3. washThe extract was washed successively with water
4. customAfter drying the
5. extractionextract over anhydrous sodium sulfate, it
6. distillationwas distilled under reduced pressure
7. customThe residue was isolated
8. custompurified by chromatography on a silica gel column (toluene:ethyl acetate=20:1-5:1)