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.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3459679PMC
http://dx.doi.org/10.1021/ol2030873DOI Listing

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