In the formal sense, four different pathways can be envisaged for the reactions of a- ketophosphoranes with the vinyl azides studied in this work: Le., reaction of the ylide with (1) the azide function16 (2) the C= C bond,'(3) the@-carbon atom of/3-azidovinyl ketones (p- ketovinylations followed by tran~ ylidation~), and (4) the C= O bond of azidovinyl ketones (Wittig reactionD).
