反应详情

温度

-78 °C

To a solution of the compound from Step A (0.20 g, 0.33 mmol) in dichloromethane (10 mL) at −78° C. was added boron trichloride (1M in dichloromethane) (3 mL, 3 mmol) dropwise. The mixture was stirred at −78° C. for 0.5 h, then at −45° C. to −30° C. for 2 h. The reaction was quenched by addition of sodium acetate (1.0 g) and methanol (10 mL). The solution was evaporated and the residue was purified by flash chromatography over silica gel using CH2Cl2 and CH2Cl2/MeOH (95:5-90:10) gradient as the eluent to furnish the desired compound (60 mg) as a solid, which was recrystallized from methanol and acetonitrile to give the title compound as an off-white solid (40 mg).

1. waitat −45° C. to −30° C. for 2 h
2. customThe reaction was quenched by addition of sodium acetate (1.0 g) and methanol (10 mL)
3. customThe solution was evaporated
4. customthe residue was purified by flash chromatography over silica gel