反应详情

温度

0 °C

Ethoxycarbonylmethylenetriphenylphosphorane (53.8 g., 0.155 mol.) was dissolved in dry dichloromethane (400 mls.) and the resulting solution was cooled to 0° C. To the cooled solution was added a solution of benzyl 4-methyl-2-oxopentanoate (34.0 g., 0.155 mol.) in dry dichloromethane (100 mls.) over a period of 25 minutes and the reaction mixture was then heated under reflux for 1 hour. The solvent was removed from the reaction mixture by evaporation in vacuo to yield an off-white solid. The solid was extracted with hexane (3×200 mls.) and the solvent was removed from the combined hexane extracts to yield a crude product as a yellow oil. The crude product was purified by distillation (0.6 mm Hg), to yield E and Z benzyl 3-(ethoxycarbonyl)-2-(2-methylpropyl)propenoate (41.0 g.) being collected at 137°-142° C.

1. temperaturethe reaction mixture was then heated
2. temperatureunder reflux for 1 hour
3. customThe solvent was removed from the reaction mixture by evaporation in vacuo
4. customto yield an off-white solid
5. extractionThe solid was extracted with hexane (3×200 mls.)
6. customthe solvent was removed from the combined hexane
7. customto yield a crude product as a yellow oil
8. distillationThe crude product was purified by distillation (0.6 mm Hg)