| 摘要 |
PURPOSE:To easily obtain the titled compound useful as an intermediate for pyrethroidal insecticide, in high efficiency and purity, by reacting a peroxide, etc., with cis-chrysanthemumic acid halides in the presence of a specific bromine compound, thereby converting the cis-compound to trans-compound. CONSTITUTION:A cis or mixed cis/trans-chrysanthemumic acid halide of formula (X is Cl or Br) (e.g. chrysanthemum-monocarboxylic acid chloride) is made to react with at least one kind of bromine compound selected from hydrogen bromide, carboxylic acid bromides (e.g. acetyl bromide), N-brominated compounds (e.g. N-bromosuccinimide), S-brominated compounds (e.g. thionyl bromide) and bromine compounds of halogen (e.g. iodine monobromide) in the presence of a peroxide (e.g. t-butyl hydroperoxide) or an azo compound (e.g. azobisisobutyric acid methyl ester) in an inert solvent (preferably toluene, etc.) at -30-100 deg.C for several min-10hr, thereby converting the cis-compound to objective trans-compound. |
