| 摘要 |
PURPOSE:To readily produce the subject compound with an ultrahigh trans ratio by irradiating an optically active dihalo acid or cis or racemic dihalo acid rich in the cis-isomer with light having a prescribed wavelength or above in the presence of N-substituted carbazoles. CONSTITUTION:An optically active dihalovinylcyclopropanecarboxylic acid expressed by formula I (X and Y are halogen; * indicates asymmetric carbon) or the cis-isomer expressed by formula II or a racemic- dihalovinylcyclopropanecarboxylic acid rich in the cis-isomer is irradiated with light having >=340nm wavelength in the presence of N-substituted carbazoles (e.g. N-methylcarbazole) expressed by formula III (R1 is alkyl, aryl or alkenyl; R2 and R3 are H, alkyl or allyl, or both are linked to form naphthalene ring) to afford racemic-dihalovinylcyclopropanecarboxylic acid rich in the trans- isomer. The aforementioned method is an industrial and advantageous method. |
