Oxidation of α-oxo-oximes to nitrile oxides with hypervalent iodine reagents.

Upon reaction with PhI(OAc)(2), α-oxo-aldoximes are oxidized to α-oxo-nitrile oxides, while α-oxo-ketoximes are converted into nitrile oxides via the oxidative cleavage of the carbonyl-imino σ bond. The nitrile oxides thus formed were trapped with norbornene or styrene in good yield. α,α'-Dioxo-ketoximes react less efficiently.