On the reaction between ethylene and cyclopentene, a radical mechanism

The bimolecular reaction equation image is shown to proceed via a simple, nonchain, radical mechanism: equation image with the net reaction the same as (1). Rate constants are estimated for each step and for each possible competing reaction and shown to yield minor or negligible side reactions in agreement with the observations of Lalonde and Back. Estimated and observed rate constants (1) and (1′) are in excellent agreement with the assumption that k' ‐1 is a typical radical disproportionation with zero activation energy. From the reported data a best value for k′ 1 is where θ = 2.303 RT kcal/mol.