反应详情

To a solution of (2S,4R)-1-benzyloxycarbonyl-2-carboxy-4-hydroxypyrrolidine (50 g) and triethylamine (63.1 ml) in tetrahydrofuran (250 ml) was dropwise added methanesulfonyl chloride (35.0 ml) with stirring at -5°-0° C. for 2 hours. After stirring for 1 hour, the mixture was poured into ice-water (500 ml) and the solution was adjusted to pH 2 with concentrated hydrochloric acid. The mixture was extracted with ethyl acetate (250 ml). The organic layer was washed in turn with 1N hydrochloric acid (250 ml×2) and brine (250 ml), dried over magnesium sulfate, and evaporated under reduced pressure to give (2S,4R)-1-benzyloxycarbonyl-2-carboxy-4-methanesulfonyloxypyrrolidine (66.21 g).

1. stirringAfter stirring for 1 hour
2. extractionThe mixture was extracted with ethyl acetate (250 ml)
3. washThe organic layer was washed in turn with 1N hydrochloric acid (250 ml×2) and brine (250 ml)
4. dry with materialdried over magnesium sulfate
5. customevaporated under reduced pressure