Total Synthesis of (+)-Chimonanthine, (+)-Folicanthine, and (-)-Calycanthine

J Org Chem. 2015 Oct 16;80(20):10309-16. doi: 10.1021/acs.joc.5b01907. Epub 2015 Oct 1.

Abstract

Facile, straightforward, and asymmetric total syntheses of (+)-chimonanthine (1), (+)-folicanthine (2), and (-)-calycanthine (3) were accomplished in four to five steps from commercially available tryptamine. The synthesis features copper-mediated asymmetric cyclodimerization of chiral tryptamine derivative, which established a new entry into constructing the sterically hindered vicinal quaternary stereogenic carbon centers of dimeric hexahydropyrroloindole alkaloids in one procedure. An unprecedented base-induced isomerization from the chimonanthine skeleton to the calycanthine skeleton was observed and facilitated the synthesis of (-)-calycanthine (3).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Indole Alkaloids / chemistry*
  • Indoles / chemical synthesis*
  • Indoles / chemistry
  • Molecular Structure
  • Naphthyridines / chemical synthesis*
  • Naphthyridines / chemistry
  • Pyrroles / chemical synthesis*
  • Pyrroles / chemistry
  • Stereoisomerism

Substances

  • Indole Alkaloids
  • Indoles
  • Naphthyridines
  • Pyrroles
  • folicanthine
  • chimonanthine
  • calycanthine