Synthesis of chromones and 4-hydroxyquinolines based on uncatalyzed condensations of 1-methoxy-1,3-bis(trimethylsilyloxy)-1,3-butadiene with 2-alkoxy- and 2-nitrobenzoyl chlorides and related reactions

Org Biomol Chem. 2009 May 7;7(9):1931-8. doi: 10.1039/b901092k. Epub 2009 Mar 20.

Abstract

The reaction of 1-methoxy-1,3-bis(trimethylsilyloxy)-1,3-butadiene with 2-methoxybenzoyl chlorides afforded 3,5-diketoesters which were transformed, by treatment with boron tribromide, into functionalized 2-hydroxychroman-4-ones or chromones. The reaction of 1-methoxy-1,3-bis(trimethylsilyloxy)-1,3-butadiene with 2-nitrobenzoyl chlorides and subsequent reduction of the nitro group afforded functionalized 4-hydroxyquinolines. Their tautomeric equilibrium was studied by NMR spectroscopy and by computational methods.

MeSH terms

  • Butadienes / chemistry*
  • Catalysis
  • Chromones / chemical synthesis*
  • Hydroxyquinolines / chemical synthesis*
  • Molecular Structure
  • Nitrobenzoates / chemistry*
  • Trimethylsilyl Compounds / chemistry*

Substances

  • 1-methoxy-1,3-bis(trimethylsilyloxy)-1,3-butadiene
  • Butadienes
  • Chromones
  • Hydroxyquinolines
  • Nitrobenzoates
  • Trimethylsilyl Compounds
  • 4-hydroxyquinoline