D. Colombani et B. Maillard, INTRAMOLECULAR HOMOLYTIC DISPLACEMENTS .2. POLAR EFFECTS IN THE HOMOLYTIC INDUCED DECOMPOSITIONS OF ALLYL PEROXIDES, Perkin transactions. 2, (4), 1994, pp. 745-752
The products of the decomposition of allyl peroxides 1-5, initiated by
tert-butyl peracetate, in three solvents-cyclohexane, dimethyl malona
te and benzene-were analysed. The formation of epoxides proved the exi
stence of an homolytic induced decomposition of the unsaturated peroxi
des by a chain process involving a free radical addition to the double
bond and an intramolecular homolytic substitution on the peroxide lin
kage. The balance of the reaction's products indicated a second way of
degradation of the peroxides: allylic hydrogen abstraction followed b
y the breaking of the peroxide bond by beta-elimination. The relative
ratios of the products generated by the eliminated alkoxy radicals YO.
and of the different epoxides produced in these reactions showed the
influence of the polar factors in the various steps of the homolytic i
nduced decomposition: i.e. hydrogen abstraction to the solvent or to t
he peroxide and addition to the double bond.