Alkali metal counterion control of enolate protonation stereoselectivity

Org Lett. 2006 Jun 22;8(13):2735-7. doi: 10.1021/ol060761s.

Abstract

[reaction: see text] Generation of the lithium salt of the norbornenol shown (M = H) followed by quenching with aqueous NH(4)Cl solution gives predominantly the beta-epimeric ketone 6. Similar production of the potassium alkoxide leads instead to the alpha-epimer (99:1). These results reveal the potential importance of alkali metal counterions as stereocontrol elements.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Ammonium Chloride / chemistry
  • Ketones / chemical synthesis*
  • Ketones / chemistry
  • Lithium / chemistry
  • Metals, Alkali / chemistry*
  • Molecular Conformation
  • Molecular Structure
  • Organometallic Compounds / chemistry
  • Protons
  • Stereoisomerism
  • Water / chemistry

Substances

  • Ketones
  • Metals, Alkali
  • Organometallic Compounds
  • Protons
  • Ammonium Chloride
  • Water
  • Lithium