反应详情

To a round-bottomed flask (3 L) under nitrogen atmosphere equipped with a Dean-Stark trap, toluene (350 mL), para-toluenesulphonic acid monohydrate (p-TSA) (1 g) and 8-(2,4,5-trifluorophenyl)-1,4-dioxaspiro[4.5]decan-8-ol (94.2 g) were added and the mixture was refluxed overnight. Additional p-TSA (1 g) was added. Refluxing was continued overnight and then the reaction was stirred at room temperature for two more days. The reaction mixture was treated with 0.1N aqueous sodium hydroxide solution (500 mL) and extracted with heptanes (500 mL). The organic layer was washed with water (3×500 mL), dried over anhydrous sodium sulfate, filtered and evaporated to yield crude product which was purified by column chromatography (silica gel, gradient 2% to 40% ethyl acetate in heptanes) to yield the title compound.

1. additionwere added
2. temperaturethe mixture was refluxed overnight
3. temperatureRefluxing
4. extractionextracted with heptanes (500 mL)
5. washThe organic layer was washed with water (3×500 mL)
6. dry with materialdried over anhydrous sodium sulfate
7. filtrationfiltered
8. customevaporated
9. customto yield crude product which
10. customwas purified by column chromatography (silica gel, gradient 2% to 40% ethyl acetate in heptanes)