Oxidative Decomposition of the Ozonide of Butadiene Rubber

1. Among the products of oxidative decomposition with acetyl hydroperoxide of the ozonide of butadiene rubber (prepared at 5°) are levulinic, formic, succinic, 1,2,4-butanetricarboxylic, 1,2,3-propanetricarboxylic and l,x,y,6-hexanetetracarboxylic acids. Levulinic acid could be formed by isomerization of 1,4-1)2-1,4-chains of the rubber macromolecule and by partial decarboxylation of β-ketoadipic acid, as well as by the peroxy-formate rearrangement in presence of acetyl hydroperoxide. 1,2,3-Propanetricarboxylic acid is more likely to be formed from 1,4-1,4-chains branched at the α -methylene group, or from 1,4-1,2-1,4-chains in which the double bonds had undergone suitable rearrangement, rather than as a result of secondary reactions during oxidative breakdown of the ozonide. 1,2,3-Propanetricarboxylic acid was also detected among the products of ozonolysis obtained under mild conditions of breakdown. 2. Products of oxidative breakdown of the ozonide of the rubber in question with hydrogen peroxide were acetic, formic, succinic, 1,2,4-butanetricarboxylic, 1,2,3-propanetricarboxylic and 1,x,y,6-hexanetetracarboxylic acids. Acetic acid could have been formed from 1,4-1,4-portions of the rubber molecule branched at the α -methylene group, as well as from isomerized 1,4-1,2-1,4-portions.