Concise total synthesis and structural revision of (+)-pestalazine B

Org Biomol Chem. 2010 Nov 21;8(22):5179-86. doi: 10.1039/c0ob00531b. Epub 2010 Sep 17.

Abstract

A convergent synthesis of the proposed structure of (+)-pestalazine B has been achieved in 4 steps using the N-alkylation of an unprotected tryptophan diketopiperazine with a 3a-bromopyrrolidinoindoline as the key step. Although its structure was confirmed by X-ray analysis, the spectroscopic data did not match those of the natural product. The versatility of the methodology allowed the preparation of several diastereomers, and the database generated led to the proposal of an isomeric structure for the natural alkaloid where the d-leucine and d-phenylalanine residues exchanged positions, which was corroborated by total synthesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaloids / chemical synthesis*
  • Alkaloids / chemistry*
  • Alkylation
  • Chemistry, Organic / methods*
  • Diketopiperazines / chemical synthesis*
  • Diketopiperazines / chemistry*
  • Indicators and Reagents
  • Indole Alkaloids / chemical synthesis*
  • Indole Alkaloids / chemistry*
  • Indoles / chemistry
  • Magnetic Resonance Spectroscopy
  • Molecular Conformation
  • Stereoisomerism
  • Tryptophan / chemistry

Substances

  • Alkaloids
  • Diketopiperazines
  • Indicators and Reagents
  • Indole Alkaloids
  • Indoles
  • pestalazine B
  • Tryptophan