反应详情

To a cooled (0° C.) solution of the product of Step D (156 mg, 0.366 mmol) in CH3CN (2 mL), were added carbon tetrabromide (182 mg, 0.55 mmol) and triphenylphosphine (144 mg, 0.55 mmol). After 30 minutes at 0° C., the reaction mixture was allowed to warm to room temperature, at which point acetone (40 mL, 0.55 mmol) was added. After 16 hours at room temperature, the reaction mixture was filtered, the filtrate was concentrated in vacuo, and the residue was purified on a silica gel flash chromatography column eluted with 5% ethyl acetate/hexanes to afford 86 mg (63 %) of the title compound (Rf =0.13, 5% ethyl acetate/hexanes).

1. additionwas added
2. waitAfter 16 hours at room temperature
3. filtrationthe reaction mixture was filtered
4. concentrationthe filtrate was concentrated in vacuo
5. customthe residue was purified on a silica gel flash chromatography column
6. washeluted with 5% ethyl acetate/hexanes