Synthesis of (S)- and (R)-5-oxo-piperazine-2-carboxylic acid and its application to peptidomimetics

J Org Chem. 2009 Nov 6;74(21):8433-6. doi: 10.1021/jo901389q.

Abstract

A straightforward synthesis of (S)- and (R)-N-Boc-5-oxo-piperazine-2-carboxylic acid is reported starting from L- or D-serine and ethyl glyoxylate. Those were evaluated as constituents in two tetrapeptides by studying their secondary structure by (1)H NMR spectroscopy. In the case of Boc-Val-(S)-PCA-Gly-Leu-OMe, two readily interconverting conformations (in a 40%:60% ratio) were observed, differing for the cis-trans isomerizaton of the tertiary amide bond, while Boc-Val-(R)-PCA-Gly-Leu-OMe displayed an equilibrium between a gamma-turn and a type II beta-turn conformation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carboxylic Acids / chemical synthesis*
  • Chromatography, High Pressure Liquid
  • Magnetic Resonance Spectroscopy
  • Models, Molecular
  • Molecular Mimicry*
  • Peptides / chemical synthesis*
  • Piperazines / chemistry*
  • Spectrometry, Mass, Electrospray Ionization
  • Spectrophotometry, Ultraviolet

Substances

  • Carboxylic Acids
  • Peptides
  • Piperazines