反应详情

温度

0 °C

First, 8.9 mL (8.0 mmol) of a 0.9 M solution of 2,4-difluorophenylmagnesium bromide prepared by the same method as that in Example 3 was cooled to 0° C., and a solution of 0.83 g (4.0 mmol) of (R)-1-chloro-3-pivaloyloxybutan-2-one in 10 mL of toluene 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 20 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 (30 mL×2). After drying over anhydrous sodium sulfate, concentration was performed under reduced pressure to obtain 1.57 g of a crude product. A quantitative analysis was performed by HPLC. Thereby, the title compound was obtained in a yield of 94% ((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. additionAfter the completion of the dropwise addition
2. waitwas continued for another 1 hour
3. customthe reaction
4. extractionextraction
5. dry with materialAfter drying over anhydrous sodium sulfate, concentration
6. customto obtain 1.57 g of a crude product