反应详情

温度

0 °C

To a mixture of tert-butanol (46 mL) and water (46 mL) was added AD-mix-β (18.6 g). The mixture was cooled to 0° C. 4-Methylene-6-chloro-8-difluoromethoxychromane (3.2 g 12.97 mmol, see step (vi) above) in tert-butanol (11 mL) and water (11 mL) was added. The mixture was stirred at 0° C. for 24 h. Sodium sulfite (19.0 g, 150.74 mmol) was added, and the mixture was allowed to warm to room temperature and stirred for 1 h. The layers were separated and the aqueous phase was extracted with EtOAc (2×). The combined ethyl acetate phases were dried (Na2SO4) and evaporated. The crude product was chromatographed on silica gel, eluting with methylene chloride:ethyl acetate (4:6), to afford 3.2 g (88%) of the sub-title compound.

1. temperatureto warm to room temperature
2. stirringstirred for 1 h
3. customThe layers were separated
4. extractionthe aqueous phase was extracted with EtOAc (2×)
5. dry with materialThe combined ethyl acetate phases were dried (Na2SO4)
6. customevaporated
7. customThe crude product was chromatographed on silica gel
8. washeluting with methylene chloride:ethyl acetate (4:6)