反应详情

To a mixture of 10 ml of ethyl acetate, 2 ml of 40% aqueous solution of chloroacetaldehyde and about 3 ml of water was added 1.0 g (12 mmoles) of sodium hydrogencarbonate while cooling with ice, and then the resulting mixture was stirred. To the reaction mixture was added dropwise 5 ml of aqueous solution containing 1.12 g of 1,3-cyclohexanedione while cooling with ice at a rate of 0.05 ml/minute. The reaction mixture was maintained at a pH of from 6.2 to 8.7 throughout the reaction. After completing the dropping, the reaction mixture was stirred at a room temperature overnight, and then acidified with sulfuric acid. After stirring the mixture for one hour, the ethyl acetate layer was separated, washed with an aqueous solution of potassium carbonate for removing the unreacted 1,3-cyclohexanedione, and then dried on magnesium sulfate. After distilling away the solvent, the residue was applied to a column of silica gel and eluted with dichloromethane to give 1.09 g (yield: 80%) of 4-oxo-4,5,6,7-tetrahydrobenzofuran.

1. temperaturewhile cooling with ice
2. temperaturewhile cooling with ice at a rate of 0.05 ml/minute
3. temperatureThe reaction mixture was maintained at a pH of from 6.2 to 8.7 throughout the reaction
4. stirringwas stirred at a room temperature overnight
5. stirringAfter stirring the mixture for one hour
6. customthe ethyl acetate layer was separated
7. washwashed with an aqueous solution of potassium carbonate
8. customfor removing the unreacted 1,3-cyclohexanedione
9. customdried on magnesium sulfate
10. distillationAfter distilling away the solvent
11. washeluted with dichloromethane