Description:
<jats:p>Abstract Various dialdehydes (1 -5) were formed by addition of dithiols to acrolein. Reaction of these dialdehydes with N-alkylhydroxylamines afforded dinitrones the two nitrone groups of which were joined by an alkylidene chain containing two sulfur atoms (6a,b-10a,b). Cycloaddition of these dinitrones with dimethyl acetylenedicarboxylate proceeded in the usual way giving bis(4-isoxazolines) (11a-15a).</jats:p>
<jats:p>However, analogous dinitrones formed by reaction of the dialdehydes with N-(4-tert-butylphenyl)</jats:p>
<jats:p>hydroxylamine could not be isolated. Instead tricyclic compounds arose in which</jats:p>
<jats:p>the central macrocyclic ring is flanked by two isoxazolidine rings (16c-20c). Obviously, the</jats:p>
<jats:p>dinitrones formed as intermediates underwent dimerization with formation of the tricyclic</jats:p>
<jats:p>compounds by cycloaddition between two nitrone groups and two tautomeric N-hydroxyenamine</jats:p>
<jats:p>moieties.</jats:p>
<jats:p>Two of the tricyclic compounds (16c and 20c) formed 1:1 complexes with NiCl<jats:sub>2</jats:sub> and FeCl<jats:sub>3</jats:sub>,</jats:p>
<jats:p>respectively.</jats:p>