反应详情

To a solution of ethyl (2S,3S)-3-[[1-(S)-[α-(R)-hydroxybenzyl]-3-methylbutyl carbamoyl]oxirane-2-carboxylate (558 mg, 1.66 mmol.) in ethanol (4 mL) was dropwise added 0.5N potassium hydroxide/ethanol solution (4.0 mL, 2.0 mmol.) under chilling with ice The mixture was stirred for 4 hours at room temperature, and made acidic to reach pH 1-2 by addition of water (40 m) and 2N hydrochloric acid (approx. 2 mL). The acidic mixture was extracted with three portions of ethyl acetate. The three extracts were combined and washed successively with water and an aqueous saturated sodium chloride solution, and then dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to give the titled compound as a white amorphous product (490 mg, yield 96%).

1. temperatureunder chilling with ice The mixture
2. extractionThe acidic mixture was extracted with three portions of ethyl acetate
3. washwashed successively with water
4. dry with materialan aqueous saturated sodium chloride solution, and then dried over anhydrous sodium sulfate
5. distillationThe solvent was distilled off under reduced pressure