Concise formal synthesis of porothramycins A and B via Zincke pyridinium ring-opening/ring-closing cascade

Org Lett. 2010 Jul 2;12(13):3093-5. doi: 10.1021/ol101035p.

Abstract

Short formal syntheses of the antitumor antibiotics porothramycins A and B from a commercially available ester of the unnatural amino acid 3-(3-pyridyl)alanine are presented. A rearrangement cascade that presumably involves a Zincke-type pyridinium ring-opening followed by cyclization of a pendant nucleophilic amide generates the salient pyrroline ring of the alkaloids.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Anthramycin / analogs & derivatives*
  • Anthramycin / chemical synthesis
  • Anthramycin / chemistry
  • Cyclization
  • Molecular Conformation
  • Pyridinium Compounds / chemistry*
  • Stereoisomerism

Substances

  • Pyridinium Compounds
  • Anthramycin
  • porothramycin B
  • porothramycin A