Kinetic studies of the high-pressure [6 + 4]π cycloaddition of tropone to cyclohexa-1,3-diene

Abstract

The kinetics of the [6 + 4]π cycloaddition of tropone to cyclohexa-1,3-diene have been studied in the temperature range 80–95 °C at pressures up to 2 000 bar in isopropylbenzene, N,N-dimethylformamide, and 1,4-dioxane. Activation parameters were in the range for a typical concerted intermolecular cycloaddition, and were mutually consistent in each solvent, but inconsistent with those reported for a high-pressure kinetic analysis of tropone and cyclopentadiene by le Noble. The effect of solvation on the cycloaddition reactions of tropone should be carefully re-evaluated.