反应详情

温度

55 °C

Into 350 ml of a water-acetone (1:6 by volume) mixture, was dissolved 10 g of 2-(1-hydroxy-3-butenyl)furan. To the solution heated at 55° C. under reflux, was added dropwise 6.6 g of polyphosphoric acid. After having been stirred at 55° C. for 96 hours, the reaction mixture was freed from the acetone by distillation and the residue was extracted twice with 300 ml of ether. The extract solution was washed with an aqueous sodium hydrogencarbonate solution, then with saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate, and freed from the solvent by distillation to obtain 8.5 g of a concentrate. The concentrate was purified by a column chromatography using 100 g of a silica gel (Wako Gel C-200) and a toluene-ether (2:1 by volume) mixture as eluent, to obtain 4.3 g (43% yield) of 4-hydroxy-5-allyl-2-cyclopentenone.

1. temperatureunder reflux
2. distillationthe reaction mixture was freed from the acetone by distillation
3. extractionthe residue was extracted twice with 300 ml of ether
4. washThe extract solution was washed with an aqueous sodium hydrogencarbonate solution
5. dry with materialwith saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate
6. distillationfreed from the solvent by distillation
7. customto obtain 8.5 g of a concentrate
8. customThe concentrate was purified by a column chromatography