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.