反应详情

94 g (277 mmol) of the compound from Example 36A are dissolved in 1.2 l of anhydrous dioxane, and 8 g (6.9 mmol) of tetrakis(triphenylphosphine)palladium(0) are added. At room temperature, 105 g (333 mmol) of tributylvinyltin are added slowly, and after the addition has ended, the mixture is heated at reflux for 21 h. The reaction solution is allowed to cool and filtered through kieselguhr. The filter cake is washed with ethyl acetate and the combined organic filtrates are concentrated to dryness under reduced pressure. The residue that remains is dissolved in dichloromethane and applied to kieselguhr. The product is chromatographed on 1.2 kg of silica gel using a gradient of cyclohexane and ethyl acetate. The product-containing fractions are combined and concentrated to dryness under reduced pressure. This gives 23 g (29% of theory) of the desired product.

1. additionafter the addition
2. temperaturethe mixture is heated
3. temperatureat reflux for 21 h
4. temperatureto cool
5. filtrationfiltered through kieselguhr
6. washThe filter cake is washed with ethyl acetate
7. concentrationthe combined organic filtrates are concentrated to dryness under reduced pressure
8. dissolutionThe residue that remains is dissolved in dichloromethane
9. customThe product is chromatographed on 1.2 kg of silica gel using a gradient of cyclohexane and ethyl acetate
10. concentrationconcentrated to dryness under reduced pressure