Xanthates as synthetic equivalents of oxyacyl radicals: access to lactones under tin-free conditions

J Org Chem. 2012 Jul 20;77(14):6332-9. doi: 10.1021/jo300939f. Epub 2012 Jul 5.

Abstract

In addition to their utility in Barton-McCombie deoxygenations, xanthates can engage in 5-exo-trig radical cyclizations to afford lactones after oxidative workup. In this paper, we describe a tin-free protocol that provides direct access to lactones via hydrolysis of labile thioketal intermediates. Analysis of several systems of varying complexity reveals that the reaction is most applicable for constrained systems in which the reacting center is prepositioned near the radical-accepting alkene.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cyclization
  • Free Radicals / chemistry
  • Lactones / chemical synthesis*
  • Lactones / chemistry
  • Molecular Conformation
  • Xanthines / chemistry*

Substances

  • Free Radicals
  • Lactones
  • Xanthines