反应详情

A solution of 0.69 g (3.0 mmol) of (S)-1-chloro-3-(tert-butyldimethylsilyloxy)butan-2-one in 5 mL of toluene was cooled to −20° C., and 5.3 mL (3.3 mmol) of a solution of 2,4-difluorophenylmagnesium bromide prepared by the same method as that in Example 3 was added dropwise thereto over a period of 15 minutes. After the completion of the dropwise addition, stirring was continued for another 2 hours, 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 a colorless oil. A quantitative analysis was performed by HPLC (under the same HPLC measurement conditions as those in Example 3). Thereby, the title compound was obtained in a yield of 91% (2R,3S)/(2S,3S)=92/8). 1H-NMR (400 MHz, CDCl3) (2R,3S) δ: 0.10 (s, 6H), 0.92 (s, 12H), 3.85 (d, 1H, J=12.0 Hz), 4.07 (d, 1H, J=12.0 Hz), 4.35 (q, 1H, J=6.6 Hz), 6.77-6.79 (m, 1H), 6.93-6.93 (m, 1H), 7.69-7.71 (m, 1H).

1. additionwas added dropwise
2. additionAfter the completion of the dropwise addition
3. waitwas continued for another 2 hours
4. customthe reaction
5. extractionextraction
6. dry with materialAfter drying over anhydrous sodium sulfate, concentration
7. customto obtain a colorless oil