AbstractIn the reactions of 2,5‐di‐tert‐butyl‐1,4‐dimethoxybezene (1) with different oxidants, the radical cation 1+.is always detectable by EPR. However, the observed reactivity of 1+.depends greatly on the oxidation systems employed. In S2O 82−Cu2+HOAc and Ce4+HOAc systems (HOAc = acetic acid), 1+.appears to have long lifetimes and does not undergo fragmentation spontaneously. In contrast, in (RFCO2)2CF2CICFCI2(F113) systems, the readily formed 1+.is short‐lived, and large amounts of de‐tert‐butylation products have been isolated. Experimental results imply that the CC bond cleavage involved in de‐tert‐butylation could be a consequence of an attack by perfluoroacyloxy radical on 1+.in their original solvent cage. The fact that addition of methanol to the reaction mixture leads to the formation of a large amount oftBuOCH3(46%) and other evidence suggest that thetert‐butyl group leaves as a carbocation. On the basis of these results, we conclude that the reactions of 1 with (RFCO2)2are initiated by electron transfer and followed by a fast coupling of various radical species, namely, 1+.with RFCO2or with RFin the solvent cage, to form σ‐complexes which collapse or react with nu