反应详情

Diethyl malonate (34.8 g.) was added to a solution of sodium (5.0 g.) in ethanol (500 ml.) and the mixture stirred for a few minutes. 3,3-Dimethyl-1-bromoallene (32.0 g.) was then added dropwise at the ambient temperature after which the mixture was refluxed for 3 hours. The ethanolic solution obtained was poured into an excess of water and the mixture extracted with chloroform (3×200 ml.). The extracts were combined, dried with anhydrous sodium sulphate and evaporated and the residual oil distilled under reduced pressure to yield ethyl 3,3-dimethyl-2-ethoxycarbonylpent-4-ynoate, as an oil b.p. 56°-60°/0.1 mm. Hg.

1. temperaturewas refluxed for 3 hours
2. customThe ethanolic solution obtained
3. extractionthe mixture extracted with chloroform (3×200 ml.)
4. dry with materialdried with anhydrous sodium sulphate
5. customevaporated
6. distillationthe residual oil distilled under reduced pressure