Difficult macrocyclizations: new strategies for synthesizing highly strained cyclic tetrapeptides

Org Lett. 2003 Jul 24;5(15):2711-4. doi: 10.1021/ol034907o.

Abstract

[reaction: see text] Cyclic tetrapeptides are an intriguing class of natural products. To synthesize highly strained cyclic tetrapeptides we developed a macrocyclization strategy that involves the inclusion of 2-hydroxy-6-nitrobenzyl (HnB) group at the N-terminus and in the "middle" of the sequence. The N-terminal auxiliary performs a ring closure/ring contraction role, and the backbone auxiliary promotes cis amide bonds to facilitate the otherwise difficult ring contraction. Following this route, the all-L cyclic tetrapeptide cyclo-[Tyr-Arg-Phe-Ala] was successfully prepared.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amides / chemistry
  • Amino Acid Sequence
  • Cyclization
  • Isomerism
  • Nitrobenzenes / chemistry
  • Oligopeptides / chemical synthesis*
  • Peptides, Cyclic / chemical synthesis*
  • Photolysis
  • Protein Conformation

Substances

  • Amides
  • Nitrobenzenes
  • Oligopeptides
  • Peptides, Cyclic