Access to dienophilic ene-triketone synthons by oxidation of diketones with an oxoammonium salt

Org Lett. 2012 Jan 20;14(2):498-501. doi: 10.1021/ol2030873. Epub 2011 Dec 29.


Here we describe the oxidation of 1,3-cyclohexanediones with 4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxoammonium tetrafluoroborate (Bobbitt's salt) to generate 5-ene-1,2,4-triones in moderate-to-good (40-80%) yields. This inexpensive oxidant facilitated an unprecedented cascade of oxidation and elimination to yield novel ene-triketones. The reactivity of these products was explored in the Diels-Alder reaction and provided moderate-to-good yields of cycloaddition products. The products described in this study represent unique, densely functionalized, and versatile building blocks for the synthesis of more complex molecules.

Publication types

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

MeSH terms

  • Cyclopentanes / chemistry
  • Ketones / chemistry*
  • Molecular Structure
  • Oxidation-Reduction
  • Quaternary Ammonium Compounds / chemistry*


  • Cyclopentanes
  • Ketones
  • Quaternary Ammonium Compounds