反应详情

A solution of 0.41 g (2.0 mmol) of (R)-1-chloro-3-pivaloyloxybutan-2-one in 5 mL of toluene was cooled to 0° C., and 3.2 mL (2.2 mmol) of a 0.69 M solution of 2,4-difluorophenylmagnesium bromide prepared by the same method as that in Example 3 was added dropwise thereto over a period of 5 minutes. After the completion of the dropwise addition, stirring was continued for another 1 hour, and 10 mL of a saturated aqueous solution of ammonium chloride was added to stop the reaction. Furthermore, 10 mL of water was added, and extraction was performed with ethyl acetate (20 mL×2). After drying over anhydrous sodium sulfate, concentration was performed under reduced pressure to obtain 0.54 g of a crude product. The resulting product was purified by column on silica gel to obtain 0.450 g of the title compound (yield: 71%) ((2S,3R)/(2R,3R)=93/7 (the diastereomeric ratio was measured by HPLC under the same HPLC measurement conditions as those in Example 19)).

1. additionwas added dropwise
2. additionAfter the completion of the dropwise addition
3. waitwas continued for another 1 hour
4. customthe reaction
5. extractionextraction
6. dry with materialAfter drying over anhydrous sodium sulfate, concentration
7. customto obtain 0.54 g of a crude product
8. customThe resulting product was purified by column on silica gel