反应详情

To a solution of the product from Step C (22.2 g, 165 mmol) in 220 mL of carbontetrachloride was added N-bromosuccinimide (29.2 g, 164 mmol) and benzoylperoxide (1.1 g). The reaction was heated to reflux for 30 minutes, then cooled to room temperature. The solution was concentrated in vacuo to one-third the original volume, poured into EtOAc, washed with water, sat. aq. NaHCO3, and brine, then dried (Na2SO4), filtered, and concentrated in vacuo to provide the crude product. Analysis by 1H NMR indicated only partial conversion, so the crude material was resubjected to the same reaction conditions for 2.5 hours, using 18 g (102 mmol) of N-bromosuccinimide. After workup, the crude material was purified by silica gel chromatography (0-10% EtOAc/hexane) to provide the desired product.

1. temperatureThe reaction was heated
2. temperatureto reflux for 30 minutes
3. concentrationThe solution was concentrated in vacuo to one-third the original volume
4. additionpoured into EtOAc
5. washwashed with water, sat. aq. NaHCO3, and brine
6. dry with materialdried (Na2SO4)
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customto provide the crude product
10. customAfter workup, the crude material was purified by silica gel chromatography (0-10% EtOAc/hexane)