反应详情

448.5 g 1,3-cyclohexanedione, 416 g 2,2-dimethyl-1,3-propanediol and 12 g p-toluenesulfonic acid were introduced into 3,000 ml methylene chloride and the mixture was heated under reflux for 24 hours using a water separator. When the reaction had ended the mixture was cooled to room temperature and 2,000 ml 32% sodium hydroxide solution were added. The phases were separated and the organic phase was washed first with sodium bicarbonate solution (44.4 g sodium bicarbonate solution/850 ml water) and then with 350 ml water. The organic phase was dried over sodium sulfate and the solvent was then evaporated in vacuo. 345 g (50% of theory) 3,3-dimethyl-1,5-dioxa-spiro[5.5]undecan-8-one were obtained in this way.

1. temperaturethe mixture was heated
2. temperatureunder reflux for 24 hours
3. customThe phases were separated
4. washthe organic phase was washed first with sodium bicarbonate solution (44.4 g sodium bicarbonate solution/850 ml water)
5. dry with materialThe organic phase was dried over sodium sulfate
6. customthe solvent was then evaporated in vacuo