反应详情

15.5 g of sodium borohydride were added in portions, whilst ice-cooling, to a solution of 20 g of ethyl (S)-α-t-butyldimethylsilyloxy-α-phenylacetate [prepared as described in step (a) above] in 500 ml of absolute methanol, and the resulting mixture was stirred overnight at room temperature. At the end of this time, 10 g of sodium borohydride were added in portions, whilst ice-cooling. The reaction mixture was then stirred at room temperature for 5 hours, after which it was concentrated by evaporation under reduced pressure, and the concentrate was mixed with water and ethyl acetate. The ethyl acetate layer was separated, washed with water and dried over anhydrous sodium sulfate, and then the solvent was removed by distillation under reduced pressure, to give the title compound as a crude product.

1. temperaturecooling
2. stirringThe reaction mixture was then stirred at room temperature for 5 hours
3. concentrationafter which it was concentrated by evaporation under reduced pressure
4. additionthe concentrate was mixed with water and ethyl acetate
5. customThe ethyl acetate layer was separated
6. washwashed with water
7. dry with materialdried over anhydrous sodium sulfate
8. customthe solvent was removed by distillation under reduced pressure