Kinetics of Peroxyradical Attack at Cyclic Hydrocarbons: Ring-Strain Effects on H-Abstraction

Article abstract of DOI:10.1002/prac.19953370113

Relative autoxidation rates were determined for the cycloalkanes C7 to C12, the methyl cycloalkanes C6 to C9 and the ethyl cycloalkanes C5 to C9 (ring size in each case) by competitive oxidation of the cycloparaffins with cumene.In the case of the methyl and ethyl cycloalkanes the reactivities of the tertiary C-H bonds coould be calculated from the amounts of tertiary alcohols formed after LiAlH4 reduction of the oxidates.As expected, the C-H reactivities are especially low in six-membered cycloparaffins and especially high in five-, seven- and eight-membered cycloparaffins.The C-H reactivity of cyclododecane lies in the same order of magnitude as the reactivities of secondary C-H bonds of normal paraffins.