Abstract
The EI mass spectra of 1,4-disubstituted-1,2,3,6-tetrahydropyridinyl derivatives were studied using ten regioselectively labeled isomers of the neurotoxin MPTP. Analysis of the isotopically enriched ions obtained from each labeled analog allowed us to identify the origins of the fragments. Fragmentation pathways are proposed that account for the formation of most of the major peaks. Based on the fragment ions detected and the calculated HOMO energies, it is proposed that electron bombardment results in a resonance delocalized radical cation that could be derived from initial electron loss from the nitrogen atom or the olefinic double bond.
