A dirhodium(II)-carbenoid route to (-)- and (+)-Geissman-Waiss lactone: synthesis of (1R,7R,8R)-(-)-turneforcidine

J Org Chem. 2001 Dec 14;66(25):8513-7. doi: 10.1021/jo010753j.

Abstract

(-)- and (+)-Geissman-Waiss lactone, 4b, was efficiently prepared via the intramolecular C-H insertion reaction of the chiral nonracemic diazoacetates (-)-5a and (+)-5b catalyzed by dirhodium(II) tetrakis[methyl (5R and 5S)-3-phenylpropanoyl-2-imidazolidinone-5-carboxylate]. The cyclization was found to proceed with excellent regioselectivity and cis-diastereoselectivity. The bicyclic lactone (-)-4b was successfully used in the synthesis of the necine base, (-)-turneforcidine 2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Lactones / chemical synthesis*
  • Lactones / chemistry
  • Magnetic Resonance Spectroscopy
  • Plants, Medicinal / chemistry
  • Pyrrolizidine Alkaloids / chemical synthesis*
  • Pyrrolizidine Alkaloids / chemistry
  • Rhodium*
  • Stereoisomerism

Substances

  • Geissman-Waiss lactone
  • Lactones
  • Pyrrolizidine Alkaloids
  • turneforcidine
  • Rhodium