| Popis: |
Open-chain bis-Reissert compounds 1 were converted to the corresponding bis-oxazolium intermediates via acid-catalyzed intramolecular cyclization. These oxazolium compounds exist in a variety of tautomeric structures in which the meso-ionic form can be intercepted by reaction with dipolarophiles in a 1,3-dipolar-cycloaddition reaction to produce a variety of highly functionalized bis-pyrrole esters 2. In turn, the bis-pyrrole esters could be converted to the corresponding bis-pyrrole tetrols 3 in high yields. J. Heterocyclic Chem., 2011. |
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