反应详情

温度

25 °C

At 25° C., 330 mg of p-toluenesulfonic acid and 1.6 ml of trimethyl orthoformate are added to a solution of 9.6 g of 2,4-bisethoxycarbonylbicyclo[3.3.0]octane-3,7-dione (preparation: Reference Example 1) in 330 ml of methanol. The mixture is stirred for 3 hours at 25° C., combined with 80 ml of 5% strength sodium bicarbonate solution, extracted three times with respectively 300 ml of methylene chloride, dried over sodium sulfate, and evaporated under vacuum. The residue is purified by chromatography on silica gel. With ethyl acetate/hexane (1+1), 7 g of the title compound is obtained as a colorless oil.

1. extractionextracted three times with respectively 300 ml of methylene chloride
2. dry with materialdried over sodium sulfate
3. customevaporated under vacuum
4. customThe residue is purified by chromatography on silica gel