| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for racemizing dihalovinyl-cyclopropanecarboxylic acids by which an expensive Lewis acid or a special photoreactional apparatus is not required. SOLUTION: An acid chlorinating agent and titanium tetrachloride are reacted with optically active 2,2-dimethyl-3-(2',2'-dihalovinyl)-cyclopropanecarboxylic acids represented by the general formula (X1 and X2 are each chlorine, bromine or fluorine atom; and Y is chlorine, bromine atom or hydroxy group) to racemize the 2,2-dimethyl-3-(2',2'-dihalovinyl)-cyclopropanecarboxylic acids. |
