Electron impact studies on α,β‐unsaturated carbonyl oximes

Electron impact studies on eight α,β‐unsaturated carbonyl oximes revealed many interesting hydrogen and skeletal rearrangements which were substantiated by deuterium labelling, exact mass measurements and metastable studies. Loss of H· and OH· as well as formation of the indenyl and fluorenyl cations and the [C9H6N]+ fragment proceed through cyclic intermediates. All the ionized oximes undergo a Beckmann rearrangement in the gaseous phase leading to intense aroyl cation peaks. Formation of the styrene radical ions and cleavage of the bond α to the oxime function have also been noticed.