Straightforward methodology for the enantioselective synthesis of benzo[a]- and indolo[2,3-a]quinolizidines

J Org Chem. 2007 Jul 6;72(14):5193-201. doi: 10.1021/jo070539g. Epub 2007 Jun 5.

Abstract

An enantioselective two-step route to substituted benzo[a]- and indolo[2,3-a]quinolizidines has been developed. It consists of (i) a stereoselective cyclocondensation of a racemic or prochiral delta-oxo(di)ester with either (S)-(3,4-dimethoxyphenyl)alaninol or (S)-tryptophanol in a process involving a dynamic kinetic resolution and/or the differentiation of enantiotopic or diastereotopic ester groups, and (ii) a subsequent stereocontrolled cyclization on the aromatic ring taking advantage of the masked N-acyl iminium ion present in the resulting oxazolopiperidone lactams.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaloids / chemistry
  • Benzene / chemistry*
  • Cyclization
  • Indoles / chemistry*
  • Molecular Structure
  • Phenylalanine / analogs & derivatives
  • Phenylalanine / chemistry
  • Quinolizines / chemical synthesis
  • Quinolizines / chemistry*
  • Stereoisomerism
  • Tryptophan / analogs & derivatives
  • Tryptophan / chemistry

Substances

  • Alkaloids
  • Indoles
  • Quinolizines
  • phenylalaninol
  • Phenylalanine
  • tryptophanol
  • Tryptophan
  • Benzene