Total synthesis of natural and unnatural lamellarins with saturated and unsaturated D-rings

J Org Chem. 2006 Dec 8;71(25):9440-8. doi: 10.1021/jo061810h.

Abstract

Twenty-eight natural and unnatural lamellarins with either a saturated or an unsaturated D-ring were synthesized according to our developed synthetic route. The key step involved the Michael addition/ring closure (Mi-RC) of the benzyldihydroisoquinoline and alpha-nitrocinnamate derivatives, which provided the 2-carboethoxypyrrole intermediates in moderate to good yields (up to 78% yield). Subsequent hydrogenolysis/lactonization furnished lamellarins with a saturated D-ring in excellent yields (up to 93% yield). DDQ oxidation of the saturated lamellarin acetates led directly to the corresponding unsaturated analogues in 54-95% yield. In addition, only two steps in our developed strategy require column chromatography.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Coumarins / chemical synthesis*
  • Coumarins / chemistry
  • Cyclization
  • Heterocyclic Compounds, 4 or More Rings / chemical synthesis*
  • Heterocyclic Compounds, 4 or More Rings / chemistry
  • Isoquinolines / chemical synthesis*
  • Isoquinolines / chemistry
  • Magnetic Resonance Spectroscopy
  • Mass Spectrometry

Substances

  • Coumarins
  • Heterocyclic Compounds, 4 or More Rings
  • Isoquinolines
  • lamellarin D