反应详情

A stirred solution of the above Compound 17a (404 mg, 1.28 mmol), N-bromosuccinimide (239 mg, 1.35 mmol) and AIBN (11 mg, 0.064 mmol) in CCl4 (3 mL) was heated to reflux and placed under a 300 W lamp for 18 h. The solution was diluted with CH2Cl2 (15 mL), extracted with H2O (3×10 mL), brine (40 mL), dried (MgSO4), filtered and concentrated. Flash chromatography (SiO2, 15-20% EtOAc-hexanes) provided the title compound (287 mg, 0.728 mmol, 57%).

1. temperatureto reflux
2. extractionextracted with H2O (3×10 mL), brine (40 mL)
3. dry with materialdried (MgSO4)
4. filtrationfiltered
5. concentrationconcentrated