反应详情

温度

70 °C

In a 100 ml flask, 2.0 g of an ethyl chrysanthemate having the optical isomer ratio of 3.6% of (-)-cis, 19.1% of (+)-cis, 10.5% of (-)-trans and 66.9% of (+)-trans forms by weight, was dissolved into 18.0 g of n-heptane under nitrogen. To the solution was added 0.7 g of aluminum chloride, and the mixture was stirred at a temperature of 70° C. for 3 hours. Thereafter, water was added to the reaction mixture to decompose the aluminum chloride. The organic layer separated was evaporated to remove the solvent, and the residue was mixed with 6.1 g of an aqueous 10% sodium hydroxide solution and stirred at a temperature of 100° C. for 2.5 hours to effect the hydrolysis. The reaction mixture was extracted with toluene to separate the neutral substance. The aqueous layer was acidified with a diluted sulfuric acid and then extracted with toluene. The toluene layer was washed with water, dried and evaporated to remove the solvent. Distillation in vacuo yielded 1.32 g of a trans-chrysanthemic acid boiling at 110° to 116° C./2 mmHg. Its analysis by gas-chromatography showed the optical isomer ratio of 0.9% of (-)-cis, 6.3% of (+)-cis, 12.4% of (-)-trans and 80.4% of (+)-trans forms by weight.

1. customThe organic layer separated
2. customwas evaporated
3. customto remove the solvent
4. additionthe residue was mixed with 6.1 g of an aqueous 10% sodium hydroxide solution
5. stirringstirred at a temperature of 100° C. for 2.5 hours
6. customthe hydrolysis
7. extractionThe reaction mixture was extracted with toluene
8. customto separate the neutral substance
9. extractionextracted with toluene
10. washThe toluene layer was washed with water
11. customdried
12. customevaporated
13. customto remove the solvent
14. distillationDistillation in vacuo