The Unorthodox Loss of Propyl from the Molecular Ions of Methoxycyclohexane

Article abstract of DOI:10.1002/oms.1210181005

It is shown by field ionization kinetics, D and 13C labelling and metastable ion studies that the loss of a propyl radical from the molecular ion of methoxycyclohexane occurs via two routes.At a molecular ion lifetime of <10^-10 s propyl is eliminated in the 'classic' way, i.e. by successive cleavage of the C(1)-C(2) bond, 1,5-H shift from C(6) to C(2) and cleavage of the C(4)-C(5) bond.At 10^-10 s the other pathway for propyl loss starts to take place, which is initiated by a hydrogen shift from position 3 or 5 to the methoxy group.This leads in a series of steps to the formation of the 3-methoxyhexene-1 ion, which eventually eliminates a propyl radical.In some of the steps specific hydrogen-deuterium exchange processes have been observed.