The Stereochemistry of Autoxidation of Methylcyclohexanes

Abstract

Abstract Autoxidation of 1, c-3, c-5- or 1, c-3, t-5-trimethylcyclohexane with oxygen in the presence of azobisisobutyronitrile at 60°C and subsequent reduction with lithium aluminium hydride gave 1, t-3, t-5- and 1, c-3, c-5-trimethyl-r-1-cyclohexanol in the same ratio of 1/0.85. Such an almost random attack of oxygen on both sides of intermediate methylcyclohexyl radicals was also observed in autoxidation of 1,2-dimethyl-, 1,4-dimethyl-, and 1,1,3,5-tetramethylcyclohexanes. Approximate relative reactivities of tertiary hydrogens in various steric environments in methylcyclohexanes towards abstraction were determined. Steric effects on the attack of oxygen and the abstraction of hydrogen are discussed.