反应详情

9 g of 2,5-dihydroxy-1,4-dioxane-2,5-dimethanol were introduced into 60 ml of dioxane and the suspension was taken to about 70° C. for 15 minutes, then taken to ambient temperature. Then, 20 ml of 3,4-dihydro-2H-pyran and 300 mg of monohydrated p-toluene sulfonic acid were added. The temperature was held at about 40° C. and then the reaction medium stood overnight at ambient temperature. It was then poured into a mixture of 300 ml of a saturated solution of sodium bicarbonate+10 ml of triethylamine and extraction was carried out 4 times with methylene chloride. The organic phase was washed with salt water and dried. After purification by passing through silica with ethyl cycloacetate/triethylamine: 8/2 as eluant, 17 g of the expected product (pale yellow syrup) were obtained.

1. customtaken to ambient temperature
2. customwas held at about 40° C.
3. waitthe reaction medium stood overnight at ambient temperature
4. washThe organic phase was washed with salt water
5. customdried
6. customAfter purification