Cyclization of the 4-cyanobutyl radical

Abstract

The rate constant for the irreversible cyclization of the 4-cyanobutyl radical to the cyclopentiminyl radical, [Formula: see text]has been measured from −52 to 12 °C by kinetic epr spectroscopy. The temperature dependence of this rate constant can be represented by,[Formula: see text]where θ = 2.3RT kcal/mol. This rearrangement is somewhat slower than the analogous cyclizations of the 5-hexenyl and 5-hexynyl radicals.