反应详情

Under an argon atmosphere, n-butyllithium (0.9 mL, 1.6 M in hexane solution, 1.5 mmol) was added to a solution of N-benzyltrimethylsilylamine (0.3 mL, 1.5 mmol) in toluene (4 mL) at −78° C. over 5 min. After stirring for 0.5 hr, a solution of (1R,2R)-1,2-dimethoxy-1,2-diphenylethane (436 mg, 1.8 mmol) in toluene (2 mL) was added, and the mixture was stirred at −78° C. for 0.5 hr. Thereto was added a solution of tert-butyl cinnamate (204 mg, 1.0 mmol) and chlorotrimethylsilane (0.63 mL, 5.0 mmol) in toluene (2 mL) over 5 min. The mixture was stirred at −78° C. for 5 hr, and quenched with saturated aqueous ammonium chloride solution (1.5 mL). After adding a saturated aqueous sodium hydrogen carbonate solution (20 mL), the mixture was extracted with ethyl acetate. The organic layer was washed with brine and dried over sodium sulfate, after which it was concentrated and subjected to silica gel column chromatography (ethyl acetate/hexane=1/25) to give the title compound (302 mg, yield 97%) as a colorless oil of [α]25D+32.5 (c 1.35, CHCl3).

1. stirringthe mixture was stirred at −78° C. for 0.5 hr
2. stirringThe mixture was stirred at −78° C. for 5 hr
3. customquenched with saturated aqueous ammonium chloride solution (1.5 mL)
4. additionAfter adding a saturated aqueous sodium hydrogen carbonate solution (20 mL)
5. extractionthe mixture was extracted with ethyl acetate
6. washThe organic layer was washed with brine
7. dry with materialdried over sodium sulfate
8. concentrationafter which it was concentrated