| 摘要 |
<p>A process of separating cis and trans isomers of cyclopropane carboxylic acids comprising the step of treating an aqueous solution of a soluble salt of the cis and trans isomers with just sufficient of an acid, for example acetic acid or carbonic acid, to cause precipitation of one isomeric form of the cyclopropane carboxylic acid whilst substantially all or a major proportion of the other isomeric form remains in solution as the soluble salt. The process may be used, for example, to separate (±)-cis-3-(2,2-dichlorovinyl)-2,2-dimethyl-cyclopropane carboxylic acid (an intermediate for insecticides) from a mixture of the (±)-cis and (±)-trans acids.</p> |
