N,N-acetals as N-acyliminium ion precursors: synthesis and absolute stereochemistry of epiquinamide

Org Lett. 2008 Sep 18;10(18):4001-3. doi: 10.1021/ol801490m. Epub 2008 Aug 15.

Abstract

A stereoselective synthesis of (+)-epiquinamide is presented in combination with determination of the absolute configuration of the natural product. Key steps in the sequence involved chemoenzymatic formation of an enantiomerically pure cyanohydrin, reductive cyclization to the corresponding cyclic N,N-acetal, and subsequent conversion into a suitable N-acyliminium ion precursor to enable construction of the second ring.

MeSH terms

  • Acetals / chemistry*
  • Animals
  • Anura
  • Biological Products / chemical synthesis
  • Biological Products / chemistry
  • Cations / chemistry*
  • Imines / chemistry*
  • Quinolizines / chemical synthesis*
  • Quinolizines / chemistry
  • Stereoisomerism
  • Substrate Specificity

Substances

  • Acetals
  • Biological Products
  • Cations
  • Imines
  • Quinolizines
  • epiquinamide