Reactions of trivalent phosphorus compounds with azides containing a mobile H-atom : A conception of phosphazo-compound spirocyclization mechanism

Investigation of the reactions of α-azidocarboxylic acids, N-(2-azidoethyl) amides and N-(2-azidoethyl) amines with trivalent P compounds shows that the intramolecular cyclization to spirophosphoranes of the intermediate phosphazo-compounds is typical of the azides of the first and third types but not of the second type. It is concluded that such cyclization is possible only where the functional group of the starting azides contains either a sufficiently mobile hydrogen atom or a highly nucleophilic proton-containing group. A new general process for producing imidazolines and oxazolines has been developed.