Ethyl chrysanthemate → Chrysanthemic Acid

Participants

Reaction Steps

To a solution of the same levo-rotatory ethyl chrysanthemate (10 g) as used in Example 12 in toluene (90 g) was added boron tribromide (0.18 g) at room temperature under a nitrogen atmosphere. Irradiation with a high pressure mercury lamp (110 W) was made for 30 minutes. After the reaction was over, similar after-treatment as in Example 12 was applied to obtain chrysanthemic acid (9.6 g). The optical isomer ratio of the product was (+)-cis, 4.0%; (-)-cis, 2.6%; (+)-trans, 42.5%; and (-)-trans, 50.9%.

Provenance & Evidence