Triflic acid-mediated rearrangements of 3-methoxy-8-oxabicyclo[3.2.1]octa-3,6-dien-2-ones: synthesis of methoxytropolones and furans

J Org Chem. 2013 Dec 6;78(23):11707-13. doi: 10.1021/jo401617r. Epub 2013 Nov 14.

Abstract

Methoxytropolones are useful scaffolds for therapeutic development because of their known biological activity and established value in the synthesis of α-hydroxytropolones. Upon treatment with triflic acid, a series of 3-methoxy-8-oxabicyclo[3.2.1]octa-3,6-dien-2-ones rearrange rapidly and cleanly to form methoxytropolones. Interestingly, bicycles that are derived from dimethyl acetylenedicarboxylate (R(2) = R(3) = CO2Me) instead form furans as the major product.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bridged Bicyclo Compounds, Heterocyclic / chemistry*
  • Furans / chemical synthesis*
  • Furans / chemistry
  • Mesylates / chemistry*
  • Molecular Structure
  • Tropolone / analogs & derivatives
  • Tropolone / chemistry

Substances

  • 3-methoxy-8-oxabicyclo(3.2.1)octa-3,6-dien-2-one
  • Bridged Bicyclo Compounds, Heterocyclic
  • Furans
  • Mesylates
  • 2-methoxytropolone
  • Tropolone
  • trifluoromethanesulfonic acid