反应详情

To a solution of cis chrysanthemic acid (2.0 g) in toluene (18 ml) was added a solution of boron tribromide (13 mg) in toluene (2.2 ml) at room temperature under a nitrogen atmosphere. Irradiation with a high pressure mercury lamp (100 W) was made for 10 minutes under stirring. After the reaction was over, similar after-treatment as in Example 1 was applied to obtain chrysanthemic acid (1.98 g). A part of the reaction solution was converted to ethyl ester. Gas chromatography assay gave the isomer ratio of the product: cis, 6.8%; and trans, 93.2%.

1. customIrradiation with a high pressure mercury lamp (100 W)