THE OXIDATION OF CINNAMALDEHYDE WITH ALKALINE HYDROGEN-PEROXIDE

The oxidation of cinnamaldehyde (3-phenyl-2-propenal) by alkaline pero xide results in epoxidation of the double bond to form cinnamaldehyde epoxide (3-phenyl-2,3-epoxy-propanal) which undergoes further reaction by ring opening and side chain cleavage to yield benzaldehyde and aci dic fragments. The reactions are first-order in the organic substrates and perhydroxyl anion and second-order overall. In the presence of al kali alone, two further reactions take place in which cinnamaldehyde a nd cinnamaldehyde epoxide side chains are cleaved by reaction with hyd roxide ion to form benzaldehyde and side chain fragments. These reacti ons are first-order in the organic substrates and hydroxide ion and se cond-order overall. Increasing solvent polarity accelerates the rates of reaction and reaction mechanisms have been proposed to describe the observed kinetic behavior. The stereoselectivity of the epoxidation r eaction has been examined in terms of an existing model for epoxidatio n of alpha,beta-unsaturated ketones by alkaline peroxide. (C) 1993 Joh n Wiley & Sons, Inc.