反应详情

640 mg (3.55 mmol) of 4,4-(1′,2′-ethylenedioxy)-bicyclo[3.2.1]oct-6-en-2-one are heated for 16 hours at a temperature of 70° C. in the presence of 200 mg of p-toluenesulfonic acid in a 2:1 mixture of acetone and water. After hydrolysis is complete (TLC monitoring: ethyl acetate/hexane 1:1), the acetone is distilled off under reduced pressure and the aqueous phase is adjusted to pH 9 with saturated sodium hydrogen carbonate solution. After extraction of the aqueous phase three times with ethyl acetate, it is acidified to pH 5 with dilute hydrochloric acid. Extraction is carried out three times with fresh ethyl acetate, followed by drying over sodium sulfate and concentration by evaporation in vacuo. 364 mg (75%) of pure bicyclo[3.2.1]oct-6-ene-2,4-dione are obtained in the form of a yellow oil for further reaction to form compounds of formula I.

1. customAfter hydrolysis
2. distillationthe acetone is distilled off under reduced pressure
3. extractionAfter extraction of the aqueous phase three times with ethyl acetate, it
4. extractionExtraction
5. dry with materialby drying over sodium sulfate and concentration by evaporation in vacuo