Cinchona alkaloid-lewis acid catalyst systems for enantioselective ketene-aldehyde cycloadditions

J Am Chem Soc. 2004 May 5;126(17):5352-3. doi: 10.1021/ja0492900.

Abstract

Asymmetric cinchona alkaloid-catalyzed acid chloride-aldehyde cyclocondensation (AAC) reactions afford enantioenriched 4-substituted and 3,4-disubstituted beta-lactones with near perfect absolute and relative stereocontrol. These reactions are characterized by the operational simplicity derived from using commercially available or easily obtained (one-step) reaction catalysts and in situ ketene generation from acid chlorides. The range of aldehyde substrates that serve as effective AAC substrates include sterically hindered aldehydes such as cyclohexanecarboxaldehyde and pivaldehyde.

Publication types

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

MeSH terms

  • Acids / chemistry*
  • Aldehydes / chemistry*
  • Catalysis
  • Cinchona Alkaloids / chemistry*
  • Ethylenes / chemistry*
  • Hydrogen-Ion Concentration
  • Ketones / chemistry*
  • Magnetic Resonance Spectroscopy
  • Molecular Structure
  • Stereoisomerism

Substances

  • Acids
  • Aldehydes
  • Cinchona Alkaloids
  • Ethylenes
  • Ketones
  • ketene