Solution thermodynamics and kinetic solvent effects on a Diels-Alder reaction

Abstract

The kinetics of the Diels-Alder condensation of maleic anhydride with 1,3-butadiene has been measured in seven solvents at 25.00°C using a vapour-pressure technique. The rate constants are used in conjunction with activity coefficient data to find the relative activity in solution of the transition state from the Brønsted-Bjerrum equation. These results show that the transition state resembles electronically the reactants rather than the product, and permit comment on the reaction mechanism and on the prediction of solvent effects for Diels-Alder reactions.