反应详情

To a solution of (2S, 3S)-3-diphenylmethylcarbamoyloxirane-2-carboxylic acid (1.80 g, 6.05 mmol.) and N-hydroxysuccinimide (696 mg, 6.05 mmol) in methylene chloride (10 mL) was added a solution of N,N'-dicyclohexylcarbodiimide (1.25 g, 6.05 mmol.) in methylene chloride (7 mL) under chilling with ice. The mixture was stirred for 30 minutes at room temperature. To the mixture was then added under chilling with ice a solution of ethylamine hydrochloride (493 mg, 6.05 mmol.) and triethylamine (0.84 mL, 6.05 mmol) in methylene chloride (7 mL). The resulting mixture was stirred overnight at 5° C. The solvent was distilled off under reduced pressure, and N,N'-dicyclohexylurea (DC-Urea) was removed by filtration after addition of ethyl acetate (10 mL). The solution was washed successively with water, 0.5N hydrochloric acid, an aqueous sodium hydrogen carbonate saturated solution, and an aqueous sodium chloride saturated solution, and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure, and the residue was purified by medium pressure silica gel column chromatography (chloroform/methanol=1/0 to 50/1), to give the desired compound as a white crystalline powdery product (928 mg, yield: 47%).

1. temperatureunder chilling with ice
2. additionTo the mixture was then added
3. stirringThe resulting mixture was stirred overnight at 5° C
4. distillationThe solvent was distilled off under reduced pressure, and N,N'-dicyclohexylurea (DC-Urea)
5. customwas removed by filtration
6. additionafter addition of ethyl acetate (10 mL)
7. washThe solution was washed successively with water, 0.5N hydrochloric acid
8. dry with materialan aqueous sodium hydrogen carbonate saturated solution, and an aqueous sodium chloride saturated solution, and dried over anhydrous sodium sulfate
9. distillationThe solvent was distilled off under reduced pressure
10. customthe residue was purified by medium pressure silica gel column chromatography (chloroform/methanol=1/0 to 50/1)