Thermal unimolecular isomerization of cyclobutenes. Part 7.—Bicyclo [3,2,0]-hept-6-ene

Abstract

The thermal isomerization of bicyclo [3,2,0]-hept-6-ene has been studied in the gas phase and in solution in the temperature ranges 274–327° and 256–288° respectively. In both phases the reaction was kinetically first order and yielded only one product, cyclohepta-1,3-diene. From the rate constants obtained at a number of temperatures in each temperature range the following Arrhenius equations were calculated: k_gas= 10^14.31 exp (–45,510/RT)sec^–1, k_solution= 10^14.65 exp (–45,860/RT)sec^–1.

The experimental results indicate that this isomerization, like the other cyclobutenes so far investigated in detail, is a true unimolecular reaction.