反应详情

In pyridine (0.6 mL) was dissolved ethyl (2S,3S)-3-[[1-(S)-[α-(R)-hydroxybenzyl]-3-methylbutyl]carbamoyl]oxirane-2-carboxylate (300 mg, 0.894 mmol.). To the resulting solution was added acetic anhydride (0.085 mL, 0.901 mol.) under chilling with ice. The mixture was stirred for 18 hours at room temperature, and extracted with ether (8 mL, 3 portions) after addition of water (10 mL). The organic portion was washed successively with water, 1N hydrochloric acid, and an aqueous saturated sodium chloride solution, and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (n-hexane/ethyl acetate=2/1), to give the titled compound as a slightly brownish crystalline product (267 mg, yield: 79%).

1. temperatureunder chilling with ice
2. extractionextracted with ether (8 mL, 3 portions)
3. additionafter addition of water (10 mL)
4. washThe organic portion was washed successively with water, 1N hydrochloric acid
5. dry with materialan aqueous saturated sodium chloride solution, and dried over anhydrous sodium sulfate
6. distillationThe solvent was distilled off under reduced pressure
7. customThe residue was purified by silica gel column chromatography (n-hexane/ethyl acetate=2/1)