Formation of 2-chloro-3-methylbutane in the thermal decomposition of 2-methylbutyl chloroformate: evidence for a 1,3-shift involving a protonated cyclopropane intermediate in a kinetically controlled substitution

Abstract

In the thermal decomposition of 2-methylbutyl chloroformate in the liquid phase, a minimum of 3% of the reaction proceeds via a 1,3-hydride shift which gives rise to the formation of 2-chloro-3-methylbutane together with some 3-methylbut-1-ene. The identification of trans-1.2-dimethylcyclopropane amongst the hydrocarbon products suggests that a protonated cyclopropane intermediate is involved.