Thermal unimolecular decomposition of 2-ethoxy-3,4-dihydro-2H-pyran

Abstract

The thermal decomposition of 2-ethoxy-3,4-dihydro-2H-pyran in the gas phase in the temperature range 288–355 °C has been studied. Ethyl vinyl ether and acrylaldehyde are formed quantitatively by a process which is homogeneous, kinetically first order, and almost certainly unimolecular. The rate constants fit the Arrhenius equation (i). Comparison of these results with those obtained for some other dihydropyran decompositions suggests that they are all concerted. log k/s^–1= 14.465 ± 0.055 –(202 090 ± 620) J mol^–1/RTln10 (i)