反应详情

温度

65 °C

At room temperature, a three-necked flask fitted with reflux condenser, internal thermometer, dropping funnel and stirrer was charged, under nitrogen protective gas, with 8.5 g of zinc powder (129 mmol) in 55 ml of ethyl acetate. After 2.4 ml of trimethylchlorosilane (19 mmol) had been added, the mixture was heated at 65° C. for 30 min, then left to cool to 50° C. Over the course of 8 min, a mixture of 15 g of 1-phenylhex-1-en-3-one, prepared by base-catalyzed aldol condensation of benzaldehyde and pentan-2-one, and 15.8 g of methyl bromoacetate (103 mmol) was added dropwise, the temperature being maintained at 50° C. by external cooling. The mixture was then stirred at 50° C. for 30 min, and following cooling to 0° C., acidified with 60 ml of 2 N hydrochloric acid to a pH of 1 and stirred for 30 min. Excess zinc was then removed by filtration and the organic phase separated. The organic phase was then stirred at 0° C. with 60 ml of 0.5 N hydrochloric acid and finally washed with 20 ml of saturated sodium hydrogen carbonate solution. Following phase separation and drying over sodium sulfate, the solvent was removed by distillation under reduced pressure. Methyl 3-hydroxy-3-(2′-phenylethenyl)caproate was obtained in a yield of 20.4 g (95% of theory) and a purity of greater than 97% (HPLC). The compound had a melting point of 43° C. following recrystallization from petroleum ether.

1. customAt room temperature, a three-necked flask fitted
2. temperaturewith reflux condenser
3. waitleft
4. temperatureto cool to 50° C
5. additionwas added dropwise
6. temperaturethe temperature being maintained at 50° C. by external cooling
7. temperaturefollowing cooling to 0° C.
8. stirringstirred for 30 min
9. customExcess zinc was then removed by filtration
10. customthe organic phase separated
11. stirringThe organic phase was then stirred at 0° C. with 60 ml of 0.5 N hydrochloric acid
12. washfinally washed with 20 ml of saturated sodium hydrogen carbonate solution
13. customFollowing phase separation
14. dry with materialdrying over sodium sulfate
15. customthe solvent was removed by distillation under reduced pressure