Substituent effects in the gas-phase eliminations of alpha;-substituted alkyl chlorides the pyrolyses of 2-chloro-3-methylbutane and pinacolyl chloride

The gas-phase pyrolyses of 2-chloro-3-methylbutane and pinacolyl chloride in the temperature range of 345-390°C and pressure range of 60-220 mm Hg are homogeneous and unimolecular in a seasoned reaction vessel. The temperature dependence of the rate constants is given by the Arrhenius equations and respectively. The Wagner-Meerwein rearrangement was not observed in these eliminations. Some correlations for the pyrolysis of α-substituted alkyl chlorides are presented and discussed. These facts are consistent with the heterolytic nature of the cyclic transition state mechanisms for these reactions.