Racemization-free synthesis of (S)-(+)-tylophorine from L-proline by radical cyclization

Org Lett. 2010 May 7;12(9):2140-1. doi: 10.1021/ol100652b.

Abstract

The phenanthroindolizidine alkaloid (S)-(+)-tylophorine was synthesized from L-proline in nine linear steps including a double bromination and a free-radical cyclization of an N-aziridinylimine as the key steps. The phenanthrene moiety was prepared from homoveratric acid and veratraldehyde and permits the variation of each oxygen-substituted ring.

MeSH terms

  • Alkaloids / chemical synthesis*
  • Cyclization
  • Indolizines / chemical synthesis*
  • Phenanthrenes / chemical synthesis*
  • Proline / chemistry*
  • Stereoisomerism

Substances

  • Alkaloids
  • Indolizines
  • Phenanthrenes
  • Proline
  • tylophorine