Electron-beam-induced fries rearrangement and oxidation reactions of sulfonic acid esters in crystalline state

Yuasa, Kanako; Enomoto, Kazuyuki*; Maekawa, Yasunari; Kato, Jun*; Yamashita, Takashi*; Yoshida, Masaru

The electron beam (EB)-induced reactions of arylsulfonic acid esters, phenyl p-toluenesulfonate (1a), phenyl benzenesulfonate (1b), and phenyl 1-naphthalenesulfonate (1c), were examined in the balk state. The EB irradiation of 1a afforded the Fries rearrangement products, o- and p-hydroxyphenyl p-tolylsulfones (2a and 3a), phenol (5), and the oxidation product of 2a, o,p-dihydroxyphenyl p-tolylsulfone (4a), which has not been observed in photolysis. The irradiation of 1b, which is liquid at room temperature, gave Fries products, 5, and the oxidation product, o,p-dihydroxyphenyl phenylsulfone. On the other hand, the EB-induced reaction of 1c proceeded with the lowest reactivity through crystal to crystal transformation to afford Fries products and 5, but not oxidation product. The mechanistic study reveals that oxidation product 4a generated by the oxidation reaction of ortho-Fries product 2a but not para-isomer 3a with an active oxidant, which should result from the decomposition of 1a.