13643-06-6Relevant articles and documents
Attempts To Trap Radicals Formed in Solution by a Magnesium Surface
Walborsky, H. M.,Topolski, M.,Hamdouchi, C.,Pankowski, J.
, p. 6188 - 6191 (1992)
The synthesis of 2,2'-azo-2-methyl-6-heptene (1) is discribed.Photolytic decomposition of 1 in ether gave rise to the 1,1-dimethyl-5-hexenyl radical clock (2) which yielded 1,1,2-trimethylcyclopentane (3), 6-methyl-1-heptene (4), and 2-methyl-1,6-heptadiene (5) in the ratio of 1:0.72:0.56, respectively.The ratio did not change appreciably when a well-stirred mixture of 1 and 5 equiv of magnesium powder was photolyzed.Moreover, the solution gave a negative test (2,2'-biquinoline) for the presence of Grignard reagent.Thus, it has been esperimentally demonstrated that the radicals formed in solution do not react with a magnesium surface to form Grignard reagents.
Radical formation in the oxidation of 2,2′-azo-2-methyl-6-heptene by thianthrene cation radical
Chen, Tonghua,Shine, Henry J.
, p. 4716 - 4719 (2007/10/03)
Reaction of 2,2′-azo-2-methyl-6-heptene (1) with thianthrene cation radical perchlorate (Th?+ClO4-) in CH2Cl2 solution containing 2,6-di-tert-butyl-4-methylpyridine (DTBMP) gave a mixture of nine C8 hydrocarbons, namely, 1,1,2-trimethylcyclopentane (4, 2.2%), 6-methyl-1-heptene (5, 2.2%), 2-methyl-1,6-heptadiene (6, 9.8%), 2,2-dimethyl-1-methylenecyclopentane (7, 2.9%), 6-methyl-1,5-heptadiene (8, 39%), 3,3-dimethyl- (9, 7.6%), 4,4-dimethyl- (10, 11%), 1,2-dimethyl- (11, 5.4%), and 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 (products 4, 5, and 7) for the formation of the 2-methyl-6-hepten-2-yl radical (2), although the major fate of 2 is its oxidation to the corresponding cation 13, the origin of the bulk of the other products.
The Thermolysis of 2,2-Dimethyl-1-vinylcyclobutane
Chickos, James S.,Frey, H. Monty
, p. 365 - 370 (2007/10/02)
The kinetics of thermolysis of 2,2-dimethyl-1-vinylcyclobutane have been investigated as a function of temperature from 263 to 301 deg C.Primary products produced in the reaction include isobutene and butadiene, 4,4-dimethylcyclohexene, 2-methylhepta-1,6-diene, and cis-2-methylhepta-1,5-diene. trans-2-Methylhepta-1,5-diene and 2,4-dimethylhexa-1,5-diene are produced from cis-2-methylhepta-1,5-diene by way of a 3,3-sigmatropic rearrangement.The reaction obeys first-order kinetics and is unaffected by surface.Activation energies (kcal mol-1) and (logA/s-1) for the overall decomposition and for formation of the primary products are 45.73 +/- 0.3 (14.427 +/- 0.12), 47.71 +/- 0.7 (15.087 +/- 0.3), 44.35 +/- 1.6 (12.53 +/- 0.6), 45.0 +/-1.3 (12.24 +/- 0.5), and 38.38 +/- 1.7 (10.785 +/- 0.7), respectively.The regiochemistry observed in fragmentation and in the 1,3-sigmatropic rearrangement of the starting material is discussed in terms of substituent effects found in other cyclobutane and vinylcyclobutane thermolyses.The fragmentation process and the isomerization to 4,4-dimethylcyclohexene and 2-methylhepta-1,6-diene is believed to proceed through the intervention of 6-methylhept-1-ene-3,6-diyl. cis-2-Methylhepta-1,5-diene is formed from a concerted 1,5-sigmatropic rearrangement of the starting material.The factors which affect the stereochemistry of the 1,5-hydrogen shift are discussed.
