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 0.1 N aqueous sodium hydroxide solution (500 mL) and extracted with heptanes (500 m-L). 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 m-L)
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)