RADICAL FORMATION IN THE OXIDATION OF 2,2'AZO-2-METHYL-6-HEPTENE BY THIANTHRENE CATION-RADICAL

Reaction of 2,2'-azo-2-methyl-6-heptene (1) with thianthrene cation ra dical perchlorate ((ThClO4-)-Cl-.-) in CH2Cl2 solution containing 2,6- di-tert-butyl-4-methylpyridine (DTBMP) gave a mixture of nine C-8 hydr ocarbons, namely, 1,1,2-trimethylcyclopentane (4, 2.2%), 6-methyl-1-he ptene (5, 2.2%), 2-methyl-1,6-heptadiene (6, 9.8%), 2,2-dimethyl-1-met hylenecyclopentane (7, 2.9%), 6-methyl-1,5-heptadiene (8, 39%), 3,3-di methyl- (9, 7.6%), 4,4-dimethyl-(10, 11%), 1,2-dimethyl-(11, 5.4%), an d 1,6-dimethylcyclohexene (12, 1.5%). The amounts of acyclic dienes (6 , 8) fell and of cyclohexenes (9, 10) rose when DTBMP was omitted from or diminished in the solution, The results provide firm evidence (pro ducts 4, 5, and 7) for the formation of the 2-methyl-6-hepten-2-yl rad ical (2), although the major fate of 2 is its oxidation to the corresp onding cation 13, the origin of the bulk of the other products.