Novel rearrangement of secondary alkoxyalkyl radicals during addition to a double bond. Steric shielding in the formation of tertiary alkoxyethyl radicals

The participation of a 1,3-hydrogen shift in initially formed secondary alkoxyethyl radicals R1R2CH-O-CH-CH3 during their free-radical chain additions to methyl 2,3,3-trifluoroacrylate has been confirmed using a deuterium marked additive. Indirect evidence has been obtained for a partial 1,3-hydrogen shift in secondary radicals CH3(CH2)n-CH-O-CH3 to primary radicals CH3(CH2)n-CH2-O-CH2. Initial formation of tertiary alkoxyethyl radicals R1R2C-O-CHR3R4 in the propagation step was not observed due to steric factors.