反应详情

To a solution of 50.6 g of trimethylsulphoxonium iodide in 400 cm3 of dimethyl sulphoxide there are added, in one go, 8.84 g of 60% sodium hydride in oil. The reaction mixture is stirred for 2 hours and then a solution of 43.3 g of diethyl ethylidenemalonate in 200 cm3 of dimethyl sulphoxide is added dropwise over a period of 15 minutes. After stirring for 16 h, a mixture of ice and 100 cm3 of 1N hydrochloric acid is added and then the reaction mixture is extracted with ether (3×200 cm3). The combined organic phases are washed with sodium chloride solution and then dried over sodium sulphate and evaporated. Chromatography on silica gel (dichloromethane/cyclohexane: 75/25) allows 37.5 g of expected product to be isolated.

1. stirringAfter stirring for 16 h
2. additionis added
3. extractionthe reaction mixture is extracted with ether (3×200 cm3)
4. washThe combined organic phases are washed with sodium chloride solution
5. dry with materialdried over sodium sulphate
6. customevaporated
7. customto be isolated