反应详情

50 g (162 mmol) of the compound from example 41A are dissolved in 700 ml of anhydrous dioxane and admixed with 62 g (194 mmol) of tributylvinyltin and 4.7 g (4.0 mmol) of tetrakis(triphenylphosphine)palladium, and the mixture is heated at reflux for 15 h. It is allowed to cool and filtered through kieselguhr. It is washed with ethyl acetate, and the combined filtrates are concentrated to dryness under reduced pressure. The residue is applied to silica gel and chromatographed on 800 g of silica gel with a gradient of cyclohexane and ethyl acetate. This affords 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. washIt is washed with ethyl acetate
6. concentrationthe combined filtrates are concentrated to dryness under reduced pressure
7. customchromatographed on 800 g of silica gel with a gradient of cyclohexane and ethyl acetate