| 摘要 |
<p>PURPOSE:To readily convert optically active chrysanthemum-monocarboxylic acids into racemic modification rich in the effective trans-isomer exhibiting powerful insecticidal activity using industrial and advantageous raw materials, by reacting an SH compound with the optionally active chrysanthemum- monocarboxylic acids in the presence of a specific compound. CONSTITUTION:Optically active chrysanthemum-monocarboxylic acids expressed by the formula (X is hydroxyl group, halogen, 1-20C alkoxy or 2,2-diemthyl-3- ixobutynylcyclopropanecarboxyl; * indicates asymmetric carbon) are reacted with an SH compound in an amount of preferably within the range of 1/500-1/2mol based on 1mol compounds expressed by the formula in the case of the chrysanthemum-monocarboxylic acid anhydride or normally within the range of 1/1,000-1/4mol based on 1mol compounds expressed by the formula in the case of other chrysanthemum-monocarboxylic acids in the presence of a peroxide or azo compound to racemize the aimed compounds. The amounts of the azo compound (preferably azonitriles) and peroxide used are 1/20-5mol based on 1mol SH compound (preferably thiophenol, etc.).</p> |
