Oxidative spirocyclisation routes towards the sawaranospirolides. Synthesis of ent-sawaranospirolides C and D

Org Biomol Chem. 2010 Jan 7;8(1):226-33. doi: 10.1039/b918091e. Epub 2009 Nov 4.

Abstract

Two routes are described for the synthesis of the sawaranospirolides, stereoisomeric spirolactone ascorbigenins isolated from Chamaecyparis pisifera. Trapping of the keto enal formed by oxidation of a functionalised 2-(4-hydroxybutyl)furan affords a potential butenolide spiroacetal precursor to sawaranospirolides A and C. Alternatively, epoxidation of protected 3-(dihydropyran-2-yl)-3-arylpropanoic acids results in spirolactonisation to generate ent-sawaranospirolide C; a related acid-mediated spirocyclisation gave access to ent-sawaranospirolide D.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chamaecyparis / chemistry*
  • Cyclization
  • Oxidation-Reduction
  • Spiro Compounds / chemical synthesis*
  • Stereoisomerism

Substances

  • Spiro Compounds
  • spirolide A
  • spirolide C
  • spirolide D