Gas-phase rearrangements of deprotonated ketoximes, ketoxime ethers, and aldoximes. A negative-ion beckmann rearrangement

Abstract

Evidence is presented which indicates that the pronounced loss of water from deprotonated ketoximes involves specific proton transfer followed by a negative-ion Beckmann rearrangement. For example, Me₂CNO^–→^–CH₂(Me)CNOH[graphic omitted][(CH₂CNMe)^–OH]→ CH₂CNCH₂^–+ H₂O. Deprotonated aldoximes, e.g. MeCHNO^–, fragment in this way, but also undergo the competing process MeCHNO^–→ MeNOH →[(MeCN)^–OH]→^–CH₂CN + H₂O. Other rearrangements occur when proton transfer to oxygen does not occur; e.g. Ph₂CNO^– [graphic omitted] PhNOPh → PhO^–+ PhCN.