摘要 |
<p>Racemization of an optically active chrysanthemic acid or its ester of the formula: <CHEM> wherein R represents a hydrogen atom, an alkyl group of 1-20 carbon atoms, a cycloalkyl group of 3-20 carbon atoms or an aralkyl group of 7-20 carbon atoms and * mark indicates asymmetric carbon atom, is effected by contacting the acid or its ester with at least one compound selected from the group consisting of a carboxylic acid bromide, a silicon bromide, an S-bromine compound, and N-bromine compound, a halo-bromine compound and an SH compound in the presence of a peroxide or an azo compound.</p> |