Free-radical acetoxy group migration: an E.P.R. spectral study

Abstract

E.p.r. spectra have been recorded for a number of radicals generated in a flow cell from cyclic ethers, 1,3-dioxolans, 1,3-dioxans, and other cyclic and acyclic substrates. The cyclic radicals do not undergo detectable fragmentation, but the rearrangement of the radical (9) derived from t-butyl acetate has been observed. The mechanism of acetoxy group migration in radicals is discussed in the light of these results.     The spectral data, including, in some cases, values of ¹³C hyperfine splitting factors, indicate that there is considerable deviation from planarity at the radical, centres of some cyclic species, and this phenomenon is accompanied by a change in sign of α-proton splitting factors. The reducing power of radicals derived from cyclic ethers has been investigated.