反应详情

温度

-78 °C

To a solution of the product from step 1 (0.5 g, 1.81 mmol) in dichloromethane (10 mL) at −78° C. was added boron tribromide (1.0 M solution in dichloromethane, 5.43 mL, 5.43 mmol) dropwise over 5-10 min. The subsequent mixture was stirred at −78° C. for an hour followed by ambient temperature for 1 h. After cooling the reaction mixture to 0° C., it was slowly added to cold water/dichloromethane (50 mL/50 mL). The organic portion was washed with water, brine, dried over anhydrous Na2SO4 and concentrated in vacuo. The crude product was purified by silica gel flash chromatography using hexane/EtOAc (gradient system) to give the title compound (0.24 g, 47%) as an off-white solid.

1. temperatureAfter cooling the reaction mixture to 0° C.
2. washThe organic portion was washed with water, brine
3. dry with materialdried over anhydrous Na2SO4
4. concentrationconcentrated in vacuo
5. customThe crude product was purified by silica gel flash chromatography