反应详情

A solution of 31.6 g of t-butyldimethylsilyl chloride in 200 ml of dimethylformamide was added dropwise, whilst ice-cooling, to a solution of 28 g of methyl (R)-3-chloromandelate (prepared as described in Preparation 47) and 28.5 g of imidazole in 300 ml of dimethylformamide, and the resulting mixture was stirred at the same temperature for 30 minutes, after which it was allowed to stand overnight at 40° C. At the end of this time, the reaction mixture was concentrated by evaporation under reduced pressure, and the residue was mixed with water and ethyl acetate. The ethyl acetate layer was separated and dried over anhydrous sodium sulfate, and then the solvent was removed by distillation under reduced pressure. The resulting residue was purified by column chromatography through silica gel, using a 1:15 by volume mixture of ethyl acetate and hexane as the eluent, to give the title compound as crystals, melting at 36°-38° C. [α]D23 -39.1° (c=1.014, chloroform)

1. waitto stand overnight at 40° C
2. concentrationAt the end of this time, the reaction mixture was concentrated by evaporation under reduced pressure
3. additionthe residue was mixed with water and ethyl acetate
4. customThe ethyl acetate layer was separated
5. dry with materialdried over anhydrous sodium sulfate
6. customthe solvent was removed by distillation under reduced pressure
7. customThe resulting residue was purified by column chromatography through silica gel
8. additionby volume mixture of ethyl acetate and hexane as the eluent