Synthesis of cis-octahydroindoles via intramolecular 1,3-dipolar cycloaddition of 2-acyl-5-aminooxazolium salts

J Org Chem. 2012 Nov 16;77(22):10416-21. doi: 10.1021/jo301600p. Epub 2012 Oct 26.

Abstract

A concise method for the diastereoselective synthesis of octahydroindoles is presented. The products contain 2-amido and 7-hydroxyl substituents. A series of 2-acyl-5-aminooxazoles were prepared in one step. Upon methylation of the oxazole nitrogen atom, the substrates underwent rapid intramolecular 1,3-dipolar cycloaddition with a tethered alkene and, after reduction with excess hydride, produced octahydroindoles with excellent diastereoselectivity. The method allows for the installation of α-quaternary stereogenic carbon atoms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkenes / chemistry*
  • Cyclization
  • Cycloaddition Reaction
  • Methylation
  • Oxazoles / chemical synthesis*
  • Oxazoles / chemistry
  • Salts / chemistry*
  • Stereoisomerism

Substances

  • Alkenes
  • Oxazoles
  • Salts