Enamine chemistry. Part XV. Mass spectra of dienamines

Abstract

The mass spectra of dienamines derived from αβ-unsaturated aldehydes and ketones have been studied. The presence of the additional double bond considerably complicates the fragmentation, compared with that of simple enamines, and cleavage α to the double bond (vinylic cleavage) or rearrangement and complex fission processes may predominate over the allylic or β-fission processes observed in simple enamines. The fragmentation of the cyclic dienamines studied is dominated by aromatisation of the unsaturated six-membered ring.