Bifunctional Even-electron Ions III. Fragmentation Behaviour of aliphatic Hydroxonium Ions Containing an Additional Carbomethoxy Group

Article abstract of DOI:10.1002/oms.1210230202

The primary and subsequent fragmentaations of the bifunctional oxonium ions R-C⁺(OH)-(CH2)n-COOCH3 (n = 0-5), a, are dominated by functional group interactions.Loss of CH3OH os the only appreciable primary fragmentation of the higher homologues, but for the lowest homologue (a₀) this reaction is missing.Instead, CO loss is observed.The next homologue (a₁) shows loss of CH2CO besides loss of CH3OH.The mode of the subsequent fragmentations is dependent on the chain length separating the functional group, and formation of cyclic ions is typical of the fragmentation behaviour of a₂ and a₃.Evidence for proton transfer from the carbonyl oxygen to the methoxy group of a protonated ester group is presented.