The Reaction of Ketoximes with Hypervalent Iodine Reagents: Beckmann Rearrangement and Hydrolysis to Ketones

Abstract We investigated the reaction of ketoximes with hypervalent iodine reagents. A combination of PhI(OAc) 2 and BF 3 ·Et 2 O promoted the Beckmann rearrangement of ketoximes, thus yielding the corresponding amides. From a detailed investigation of the reaction, we determined that the Beckmann rearrangement is preceded by acetylation of the hydroxy group of the ketoxime in situ, accelerating the Beckmann rearrangement. We confirmed that the acetylated ketoxime undergoes the Beckmann rearrangement with BF 3 ·Et 2 O. The reaction of ketoximes with Koser’s reagent [PhI(OH)OTs] in the presence of tetrahydrofuran results in hydrolysis, affording the corresponding ketones in high yields at room temperature.