反应详情

50 g (162 mmol) of the compound from Example 12A are dissolved in 700 ml of anhydrous dioxane, 62 g (194 mmol) of tributylvinyltin and 4.7 g (4 mmol) of tetrakis(triphenylphosphine)palladium are added and the mixture is heated at reflux for 15 h. The mixture is allowed to cool and filtered through kieselguhr. The filter cake is washed with ethyl acetate and the combined filtrates are evaporated to dryness under reduced pressure. The residue is applied to silica gel and chromatographed on 800 g of silica gel using a gradient of cyclohexane and ethyl acetate. This gives 27 g (62% of theory) of the desired product.

1. temperaturethe mixture is heated
2. temperatureat reflux for 15 h
3. temperatureto cool
4. filtrationfiltered through kieselguhr
5. washThe filter cake is washed with ethyl acetate
6. customthe combined filtrates are evaporated to dryness under reduced pressure
7. customchromatographed on 800 g of silica gel using a gradient of cyclohexane and ethyl acetate