Linoleic acid was isomerized in (HOCH(2))(2) or glycerol in presence of KOH or NaOH at 80-160 degrees C to conjugated I (CLA) (yield 99.3%) contg. 9-cis,11-trans-I (48.5%) and 10-trans, 12-cis-I (48.3%) isomers. The product was esterified with MeOH in presence of H(2)SO(4) to resp. Me esters of (CLA). The isomeric (CLA) esters were sepd. by low-temp. crystn. in AcMe at -75 degrees C to -50 degrees C. The esters were hydrolyzed to pure isomers of (CLA). The chem. structure of the intermediates and products was confirmed by NMR spectroscopy. The optimum conditions for the isomerization and crystn. were established. The isomeric purity of the (CLA) Me esters was 84% and 97%, resp.