Oxidative Cyclization of Acyclic Aryl-Substituted N-Vinylurethanes

Article abstract of DOI:10.1021/jo00293a016

Oxidation of the acyclic N-(1-(1-naphthyl)vinyl)urethane (3) with lead tetraacetate (LTA) forms a naphthyloxazolone as the major product, accompanied by the product of rearrangement, N-(ethoxycarbonyl)-1-naphthylacetamide.When the naphthyl group is replaced by alkoxy-substituted aromatic rings, the N-vinylurethane undergoes three successive oxidations by LTA leading to novel substituted nitrogen containing cyclic anhydrides, oxazolidine-2,5-diones.The structure of this unusual oxidation product was proven by X-ray analysis.The mechanism of the oxidation is discussed in terms of known enamide oxidations, and the intermediacy of an oxazolone is demonstrated.