反应详情

To a fresh solution of sodium ethoxide prepared from 23 g (1.0 mole) of sodium and 700 ml of absolute ethanol is added 168.2 g (1.05 mole) of diethyl malonate and 114.24 g (1.02 mole) of distilled 5-methyl-3-hexene-2-one. The mixture is refluxed for 1 hour; an additional 125 ml of ethanol added; and refluxing continued for two more hours. A solution of 123.4 g of potassium hydroxide in a 600 ml of water is then added and the reaction mixture refluxed for 6 hours. The mixture is then neutralized with 12% hydrochloric acid to pH 4. The ethanol is distilled and the mixture treated with three 15 g portions of activated charcoal. The hot reaction mixture is filtered through filter aid after acidification to pH 2. The product is extracted with hot isopropyl ether (700 ml). Cooling of the isopropyl ether layer results in 60.5 g (40% yield) of the product, m.p. 52°- 65° C.

1. temperatureThe mixture is refluxed for 1 hour
2. temperatureand refluxing
3. temperaturethe reaction mixture refluxed for 6 hours
4. distillationThe ethanol is distilled
5. additionthe mixture treated with three 15 g portions of activated charcoal
6. filtrationThe hot reaction mixture is filtered
7. filtrationthrough filter aid after acidification to pH 2
8. extractionThe product is extracted with hot isopropyl ether (700 ml)
9. temperatureCooling of the isopropyl ether layer