反应详情

54.6 mg of pyridinium p-toluenesulphonate (0.217 mmol) were added to a solution of the acetal from Example 64A (400 mg, 0.725 mmol) in 15 ml of acetone/water (10:1) and the mixture was stirred under reflux for 3 d, with another 54.6 mg of pyridinium p-toluenesulphonate (0.217 mmol) being added after 24 h and 48 h. The solvent was then removed under reduced pressure, the residue was taken up in water and the mixture was extracted with dichloromethane. The organic phase was dried over magnesium sulphate, filtered and concentrated under reduced pressure. Yield: 363 mg (92% of theory)

1. additionbeing added after 24 h and 48 h
2. customThe solvent was then removed under reduced pressure
3. extractionthe mixture was extracted with dichloromethane
4. dry with materialThe organic phase was dried over magnesium sulphate
5. filtrationfiltered
6. concentrationconcentrated under reduced pressure