Ozonolysis of cinnamic acid in water medium

The ozonolysis of trans-cinnamic acid (trans-3-phenyl-acrylic acid) in aque ous medium is studied in this paper. In acid medium, benzaldehyde was forme d in a 1:1 ratio with respect to both cinnamic acid and ozone consumption t hroughout the reaction. Simultaneously, significant amounts of organic pero xides were measured in the reaction mixture, which proved to be stable duri ng one hour or more. These facts suggest that in the reaction mechanism, th e carbonyl group is preferentially formed in the aryl side of the former do uble bond, while the Criegee's carbonyl oxide (zwitterion) is formed in the alkyl moiety. An explanation based on the stabilization of the carbonyl ox ide alkyl moiety by the influence of the neighbor carboxyl group, reinforce d by water solvation, is advanced.