Method for racemization of chrysanthemic acid or its ester.

摘要

Racemization of optically active, particular­ly (-)-form of chrysanthemic acid or its ester of the formula:
<Chemistry id="chema01" num="0001"><Image id="ia01" he="36" wi="89" file="IMGA0001.TIF" imgContent="chem" imgFormat="TIFF" /></Chemistry> wherein R is, for example, hydrogen or an alkyl group, is effected by contacting it with boron tribromide or aluminium tribromide in the presence of an azo compound. This racemization is useful from a commercial point of view.