Liquid phase oxidation of α‐pinene initiated by ozone. 1. Conversion of α‐pinene and formation of its hydroperoxide

The use of ozone as initiating agent in the liquid phase oxidation of α‐pinene has been investigated. The first intermediate product of the reaction is the hydroperoxide of α‐pinene. Both, ozone partial pressure and its initiation time exert an inhibiting effect on the conversion of α‐pinene but yield higher selectivities for the hydroperoxide of α‐pinene compared with those of oxidation without ozone. In all cases, temperature was found to be the most important variable affecting the oxidation rate. From a mechanism of radical reactions, kinetic equations, consistent with the experimental results, corresponding to α‐pinene oxidation rate and net formation rate of its hydroperoxide, were obtained. The rate constants are given as functions of temperature. The results also suggest that a fraction of the hydroperoxy radicals decomposes to yield other products such as verbenol and verbenone, identified in this work, and whose kinetics will be reported in a later paper.