The products of partial hydrogenation of higher monoethylenic esters

Abstract

The formation of “iso-oleic” acids during hydrogenation of oleic (Δ 9 : 10 - octadecenoic) acid or its esters is of importance in connection with the general theory of catalytic action at solid surfaces. The constitution of these isomeric acids has therefore been re-examined by means of the oxidising action of potassium permanganate upon hot acetone solutions of their unsaturated esters, a method which has been shown to break such compounds up almost quantitatively into derivatives of the corresponding monobasic and dibasic acids:- CH 3 . [CH 2 ] x . CH : CH. [CH 2 ] y . COOR → CH 3 . [CH 2 ] x . COOH + COOH. [CH 2 ] y . COOR. Moore has already shown that during hydrogenation a state of equilibrium is reached between the amounts of ordinary oleic acid present and the isomeric forms, and that the latter include elaidic acid together with one or more isooleic acids produced by migration of the ethylenic linkage (Δ 11 : 12 -octadecenoic acid being suggested as a possible product).