反应详情

25.7 g of 4-acetyl-5-oxohexanoic acid ethyl ester and 0.3 g of 1,8-diazabicyclo-[5.4.0]-undec-7-ene were mixed, and 35 g of fumaric acid diethyl ester was added at room temperature over 40 minutes. After stirring for 24 hours, the amount of 1,8-diazabicyclo-[5.4.0]-undec-7-ene was doubled and stirring continued until conversion was complete. 0.5 g of acetic acid and 50 ml of diethyl ether were added, and the solution was extracted with an aqueous potassium carbonate solution and water. Fractional distillation of the dry organic layer yielded 25.6 g of 4,4-diacetyl-5-(ethoxycarbonyl)-heptanedioic acid diethyl ester (boiling point: 170° C./0.002 mbar; purity: 93%; colorless). Content of the active structural element C3O2: 18%.

1. stirringstirring
2. extractionthe solution was extracted with an aqueous potassium carbonate solution and water
3. distillationFractional distillation of the dry organic layer