PROCESS FOR RACEMIZATION OF CHRYSANTHEMIC ACID AND ITS ESTERS, AS WELL AS FOR CONVERSION OF THE RACEMIC MIXTURE
摘要
<p>Racemization of optically active chrysanthemic acid or its ester of the formula: <CHEM> wherein R represents hydrogen atom or an alkyl, cycloalkyl or aralkyl group of 1-20 carbon atoms and * indicates asymmetric carbon atom, is effected by contacting it with hydrogen bromide or a phosphorus bromide compound. This method may also be effected in the presence of a peroxide or an azo compound. Further, the method of the present invention can also be used for conversion of racemic cis isomer or racemic mixture of cis and trans isomers of chrysanthemic acid into corresponding racemic trans-rich isomer.</p>
