反应详情

To a solution of compound 36 (33 g, 0.073 mol) in dry DMF (200 mL) was added triphenylphosphine (29 g, 0.11 mol) with vigorous stirring at RT. The reaction mixture was cooled to 0° C., added CBr4 (36 g, 0.11 mol) portion wise over a period of 30 min and allowed to stir at RT for 24 h. The reaction mixture was cooled to 0° C., added saturated NaHCO3 solution (100 mL) and extracted with ethyl acetate (4×150 mL). The combined organic layer was dried, concentrated under vacuum and the crude product was purified by column chromatography on silica gel (50% ethyl acetate in hexane) to give the title compound (22 g, 57%). TLC: 100% EtOAc, Rf=0.7

1. temperatureThe reaction mixture was cooled to 0° C.
2. stirringto stir at RT for 24 h
3. temperatureThe reaction mixture was cooled to 0° C.
4. extractionextracted with ethyl acetate (4×150 mL)
5. customThe combined organic layer was dried
6. concentrationconcentrated under vacuum
7. customthe crude product was purified by column chromatography on silica gel (50% ethyl acetate in hexane)