No abstract

Condensation of 2,4-diaminobutyric acid (Dab) with other amino acids yields tetrahydropyrimidine derivatives. Such condensation products can be constituents of the peptide chain of pyoverdins and ferribactins (the siderophors of fluorescent pseudomonads). Synthesis of several representatives and model substances allows to confirm earlier structural conclusions based mainly on NMR evidence. Apparent anomalies accompanying the derivatization for GC/MS analysis could be clarified.

Mass spectrometric fragmentation and especially rearrangement reactions of dialkyl selenides after electron ionization will be discussed.