Total syntheses of (+)- and (-)-pestalotiopsin A

J Org Chem. 2009 Sep 4;74(17):6452-61. doi: 10.1021/jo9012546.

Abstract

An enantioselective total synthesis of both enantiomers of caryophyllene-type sesquiterpenoid pestalotiopsin A has been achieved, thereby establishing the absolute stereochemistry of natural (+)-pestalotiopsin A. Highlights of the synthesis include a [2 + 2] cycloaddition of N-propioloyl Oppolzer's camphorsultam and ketene dialkyl acetal and subsequent highly stereoselective 1,4-hydride addition/protonation, an aldol reaction of functionalized bicyclic lactone with aldehyde, an efficient intramolecular Nozaki-Hiyama-Kishi (NHK) reaction for the construction of the highly strained (E)-cyclononene ring, and a palladium-catalyzed reduction of allylic mesylate with retention of the E configuration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aldehydes / chemistry
  • Catalysis
  • Chemistry, Organic / methods
  • Cyclization
  • Inhibitory Concentration 50
  • Lactones / chemistry
  • Models, Chemical
  • Molecular Structure
  • Palladium / chemistry
  • Sesquiterpenes / chemical synthesis*
  • Sesquiterpenes / chemistry
  • Stereoisomerism
  • X-Ray Diffraction

Substances

  • Aldehydes
  • Lactones
  • Sesquiterpenes
  • pestalotiopsin A
  • Palladium
  • 3-hydroxybutanal