The present invention is to provide the process for preparing racemized cyclopropanecarboxylic acids or their acid anhydrides from the corresponding optically active, particularly levo-rotatory, cyclopropanecarboxylic acid anhydrides. The racemization is effected by the treatment of the optically active acid anhydride with a Lewis acid. Thus, the present racemization process enables more efficient commercial production of dextro-rotatory cyclopropanecarboxylic acids, which are the more effective acid component of pyrethroidal insecticides, when combined with an optical resolution process.
本发明提供了一种从相应的光学活性
环丙烷羧酸酐制备消旋
环丙烷羧酸或其酸酐的过程。消旋化是通过用
路易斯酸处理光学活性酸酐来实现的。因此,本消旋化过程使得更有效的商业生产右旋
环丙烷羧酸成为可能,这是拼氏
杀虫剂更有效的酸成分,当与光学分辨过程相结合时。