反应详情

Ethyl 2-(diethylphosphono)propanoate (23.9 g.) was added to dry toluene (250 mls.) containing 80% sodium hydride in mineral oil (3.0 g.) at room temperature. The resultant mixture was heated to 50°-60° C. for 5 minutes and then cooled to -30° to -40° C. To the cooled mixture was added benzyl 4-methyl-2-oxopentanoate (20 g.) and the resulting mixture was allowed to warm to room temperature over a period of 1 hour. The toluene solution was washed with dilute citric acid (50 mls.), water (2×50 mls.) and then dried over anhydrous sodium sulfate. The toluene was removed by evaporation in vacuo to yield E and Z benzyl 3-(ethoxycarbonyl)-2-(2-methylpropyl)butenoate as a mixture of isomers in the form of an oil.

1. temperaturecooled to -30° to -40° C
2. washThe toluene solution was washed with dilute citric acid (50 mls.), water (2×50 mls.)
3. dry with materialdried over anhydrous sodium sulfate
4. customThe toluene was removed by evaporation in vacuo