Phenylacetaldehyde (PAA) and benzyl alcohol (BAl) are formed in oxygen atmosphere from styrene epoxide in the presence of p- toluenesulfonic acid (TSA) in a solution of 90 vol % tert-butanol with 10 vol % chlorobenzene (BUC). The ratio of the propagation (k (2) ) to the termination (k (6)) rate constants has been measured to be k (2)/aek (6) = 8.6 x x 10(-3) (L/(mol s))(1/2) at 343 K by the method of initiated oxidation of PAA in a BUC solution. One of the products of the radical chain PAA oxidation is BA. This reaction leads to BAl accumulation during the conjugated oxidation of PAA with the epoxide in an acid alcohol medium. The contribution of BAl formed to the oxidation is almost unnoticeable.