Gas-Phase Pyrolysis Kinetics of 5-Acetoxy-2-methylpent-2-ene

Article abstract of DOI:10.1021/j150609a029

The kinetics of the gas-phase pyrolysis of 5-acetoxy-2-methylpent-2-ene has been measured over the temperature range 330-380 deg C and pressure range 53-210 torr.The reaction, in a static system seasoned with allyl bromide, and in the presence of propene inhibitor, is homogeneous, obeys a first-order law, and is unimolecular.The rate constants are given by the Arrhenius equation log k(s^-1) = (13.21+/-0.14)-(199.6+/-1.7)kJ mol^-1(2.303RT)^-1.The presence of the (CH3)2C=CH group at the β-carbon atom of ethyl acetate does not provide anchimeric assistence in the elimination of this ester.A simultaneous effect of both steric acceleration and the allylic weakening of the β hydrogen appears to cause a slight rate enhancement of the Z=(CH3)2C=CH group relative to Z=CH2=CH group in the pyrolysis of ZCH2CH2OAc.