GB925148A - Process for catalytic isomerisation of compounds of unconjugated polyethenoid acids - Google Patents

Abstract

Conjugated esters, amides and polyamides of polyethenoid acids and mixtures thereof are prepared by the catalytic isomerisation of the unconjugated polyethenoid compound or compounds, at between 60 DEG and 180 DEG C., with 0.05 to 5.0% by weight of an alkali metal alcoholate as catalyst, and in the absence of compounds such as water, free fatty acids and peroxides which will inactivate the catalyst. Esters of monohydric alcohols and linoleic, linolenic, arachidonic and tri-, tetra-, penta-, and hexethenoid acids, or amides of these acids may be used. The catalysts may be formed by reacting alkali metals, hydrides or amides thereof with methyl, ethyl, propyl or butyl alcohol, and the activity increased by the addition of monohydric alcohols and the reaction may be carried out in solvents such as heptane, dimethyl formamide and dimethyl sulphoxide. Examples describe the treatment of (1) the methyl, ethyl, propyl and butyl esters of soya bean fatty acids using potassium methylate, ethylate, propylate and butylate, (2) the propyl ester of cotton seed fatty acids with potassium methylate and isopropylate, (3) the methyl ester of fish oil fatty acids with caesium t-butylate, and an amine, e.g. ethylene diamine, and (4) the amides of soya bean fatty acids prepared by treatment of the methyl ester with ethylene diamine with potassium methylate. Interesterification and amination may take place during the isomerisation.