β-Peroxyalkyl radicals and their role in the generation of epoxides during the autoxidation of alkenes. An example of the interplay of free radical, peroxide and organometallic chemistries

Article abstract of DOI:10.1016/0022-328X(92)83431-G

The systematics of the γ-scission reactions of β-peroxyalkyl radicals to yield epoxides have been extended to include variations in the degree of alkylation at the α- and β-carbon atoms and in the nature of the departing alkoxyl radical.The ratios of geometrically isomeric epoxides so produced have been shown to be dependent upon the steric bulk of the C_α- and C_β-substituents but rather independent of the nature of the departing alkoxyl radical.The relative importance of 1,5-H atom transfer in β-peroxyalkyl radicals has been considered and some evidence forits occurrence adduced.The relevance of these findings to published data for alkene autoxidation is discussed in terms of two competing pathways, in which, it is suggested, steric factors determine the outcome.