On the Substituent Effects of the Thermal Ethenylcyclopropane-to-Cyclopentene Rearrangement: Gas-Phase Kinetics of Ethoxy-, Methylthio- and Trimethylsilyl-Substituted Ethenylcyclopropanes
作者:Gregory McGaffin、Bernd Grimm、Ute Heinecke、Holger Michaelsen、Armin de Meijere、Robin Walsh
high yields and subjected to gas-phase pyrolytic kinetic investigations. All ethenylcyclopropanes rearranged cleanly to the correspondingly substituted cyclopentenes, although in the case of the 2-substituted compounds, cis/trans isomerization was additionally observed (both stereoisomers were investigated in these cases). All rearrangements obeyed first-order kinetics independent of pressure and surface-to-volume
Synthetic methods for the valene type valence isomers6a,b and Dewar type isomers 7a,b of azulene have been elaborated utilizing the same intermediate 12a. Cyano-Dewar heptalene 9 has also been synthesized. Thermal and photochemical isomerizations of these prototype molecules are discussed briefly.