反应详情

A borane-tetrahydrofuran complex (1.0 M solution in tetrahydrofuran, 60 ml, 60 mmol) was added dropwise over 15 min to a (S)—CBS solution ((S)-2-methyl-CBS-oxazaborolidine, 12 ml, 1.0 M solution in toluene) at −30° C., and the mixture was stirred for 15 min. A solution of 4-fluorophenacyl chloride (10.4 g, 60 mmol) in dichloromethane (16 ml) was added dropwise over 60 min keeping the temperature −32° C. to −28° C. After stirring for 1 hr, the solution was allowed to warm to room temperature, and methanol (20 ml) was added slowly and then 1 M hydrochloric acid (120 ml) was added dropwise over 10 min. The reaction mixture was filtered after stirring for 40 min, and the filtrate was extracted with ethyl acetate. The combined organic layer was washed successively with 1 M hydrochloric acid and brine, and dried over anhydrous sodium sulfate. The organic layer was concentrated to give 2-chloro-(1S)-1-(4-fluorophenyl)ethanol (10.4 g) as a colorless oil.

1. customthe temperature −32° C. to −28° C
2. stirringAfter stirring for 1 hr
3. filtrationThe reaction mixture was filtered
4. stirringafter stirring for 40 min
5. extractionthe filtrate was extracted with ethyl acetate
6. washThe combined organic layer was washed successively with 1 M hydrochloric acid and brine
7. dry with materialdried over anhydrous sodium sulfate
8. concentrationThe organic layer was concentrated