Stereoselective construction of an unprecedented 7-8 fused ring system in micrandilactone a by [3,3]-sigmatropic rearrangement

Org Lett. 2008 Feb 21;10(4):665-8. doi: 10.1021/ol703126q. Epub 2008 Jan 24.

Abstract

The 7-8 bicyclic ring system of micrandilactone A (1) with the required stereochemistry and functional groups was constructed by a Bu3Al-promoted Claisen rearrangement. Computational studies indicated that the exocyclic vinyl ether undergoes a [3,3] sigmatropic process via a chairlike transition state to afford exclusively the Z-double bond in the newly generated 8-membered ring with a high level of chirality transfer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Cyclization
  • Lactones / chemical synthesis*
  • Lactones / chemistry
  • Lactones / isolation & purification
  • Molecular Structure
  • Plants, Medicinal / chemistry*
  • Schisandra / chemistry*
  • Stereoisomerism
  • Triterpenes / chemical synthesis*
  • Triterpenes / chemistry
  • Triterpenes / isolation & purification

Substances

  • Lactones
  • Triterpenes
  • micrandilactone A
  • rubriflorin A