Conjugate additions to phenylglycinol-derived unsaturated delta-lactams. Enantioselective synthesis of uleine alkaloids

J Org Chem. 2004 Dec 10;69(25):8681-93. doi: 10.1021/jo0487101.

Abstract

The stereochemical outcome of the conjugate addition of a variety of stabilized nucleophiles (2-indoleacetic enolates and sulfur-stabilized anions) to the phenylglycinol-derived unsaturated lactams trans-2, cis-2, and its 8-ethyl-substituted analogue 10 is studied. The factors governing the exo or endo facial stereoselectivity are discussed. This methodology provides short synthetic routes to either cis- or trans-3,4-disubstituted enantiopure piperidines as well as efficient routes for the enantioselective construction of the tetracyclic ring system of uleine alkaloids, both in the normal and 20-epi series. The formal total synthesis of several alkaloids of this group is reported.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaloids / chemical synthesis*
  • Bridged-Ring Compounds / chemical synthesis*
  • Crystallography, X-Ray
  • Ethanolamines
  • Glycine / analogs & derivatives*
  • Glycine / chemistry*
  • Lactams / chemical synthesis*
  • Molecular Conformation
  • Stereoisomerism

Substances

  • Alkaloids
  • Bridged-Ring Compounds
  • Ethanolamines
  • Lactams
  • uleine
  • N-phenylethanolamine
  • Glycine