反应详情

A solution of the product obtained in Example IV (2.7 g, 0.017 mol) and p-toluenesulfonic acid monohydrate (0.023) g, 0.12 mmol) in dry toluene (200 ml) was allowed to reflux through a Soxhlet extractor for 2 hours. The Soxhlet thimble was charged with Type 4 A molecular sieves (16 g). After the solution was cooled to room temperature, anhydrous potassium carbonate (5 g, 0.036 mol) was added to the solution, and the mixture was stirred at room temperature for 30 min. The mixture was filtered and subjected to rotary evaporation to afford a slightly yellow wax at a 68% yield. Recrystallization from ethyl ether gave white crystals having a melting point of 69° C.

1. temperatureto reflux through a Soxhlet extractor for 2 hours
2. additionThe Soxhlet thimble was charged with Type 4 A molecular sieves (16 g)
3. filtrationThe mixture was filtered
4. customsubjected to rotary evaporation
5. customto afford a slightly yellow wax at a 68% yield
6. customRecrystallization from ethyl ether
7. customgave white crystals