反应详情

Into a 2 l. 3-neck flask equipped with stirrer, condenser, thermometer, dropping funnel, and under a nitrogen atmosphere is placed 325 ml. of ethanol, and 2.5 g. of freshly cut sodium is added. When solution of the sodium is effected, 200 g. of diethyl methyl malonate is added in 5 minutes, and the mixture is stirred at room temperature for 1 hour. At the end of this period a solution of 100 g. of 2-cyclohexen-1-one in 130 ml. of ethanol is added through the dropping funnel over a period of 1 hour. The ensuing mild exothermic reaction causes the temperature to rise to 42°. Stirring is continued overnight at room temperature, after which 20 ml. of acetic acid is added, and the mixture is evaporated at reduced pressure. The residual oil is dissolved in 1.31 l. of ether, transferred to a separatory funnel and washed with three 230 ml. portions of water. The ether solution is dried over anhydrous sodium sulfate, filtered, and dried over anhydrous calcium sulfate. The ether is removed at reduced pressue and the residual oil distilled under high vacuum using a 6-inch Vigreux column. After removal of a forerun of 22.5 g., bp 49°-129°/0.14-0.21 mm, α-methyl-3-oxocyclohexane malonic acid diethyl ester distills at 129°-130°/0.2 mm; 211.5 g, 75.4% of theory.

1. custom3-neck flask equipped with stirrer, condenser
2. customThe ensuing mild exothermic reaction
3. customto rise to 42°
4. stirringStirring
5. waitis continued overnight at room temperature
6. customthe mixture is evaporated at reduced pressure
7. dissolutionThe residual oil is dissolved in 1.31 l
8. customof ether, transferred to a separatory funnel
9. washwashed with three 230 ml
10. dry with materialThe ether solution is dried over anhydrous sodium sulfate
11. filtrationfiltered
12. dry with materialdried over anhydrous calcium sulfate
13. customThe ether is removed
14. distillationthe residual oil distilled under high vacuum
15. customAfter removal of a forerun of 22.5 g
16. distillation, bp 49°-129°/0.14-0.21 mm, α-methyl-3-oxocyclohexane malonic acid diethyl ester distills at 129°-130°/0.2 mm