反应详情

3.0 g (17.8 mmol) of ethyl 7-oxabicyclo[2.2.1]hept-5-en-2-carboxylate are suspended in 10 ml of water and 20 ml of ethanol. The temperature is kept below 20° C. by cooling with ice, while 3.5 g (62.3 mmol) of potassium hydroxide are added. The mixture is stirred for 2 hours at ambient temperature, the ethanol is distilled off at a bath temperature of 30° C. and the aqueous solution is extracted with ethyl acetate. The aqueous phase is acidified to a pH of 6 while cooling with ice and shaken with dichloromethane, then the combined organic extracts are dried and evaporated down. 0.8 g (32% of theory) of the title compound are obtained as a brown oil.

1. customis kept below 20° C.
2. additionare added
3. distillationthe ethanol is distilled off at a bath temperature of 30° C.
4. extractionthe aqueous solution is extracted with ethyl acetate
5. temperaturewhile cooling with ice
6. stirringshaken with dichloromethane
7. customthe combined organic extracts are dried
8. customevaporated down