3 4 In,this case, too, the fragmentation pattern (Scheme 4) confirms the as&& structure. Tbe detaikd frag- mentation data are given in Tabk 2. The mokcukr ion is absent or of snudl intetudty, but tbe mokcukr weight is con6rmed by the presence of M+l ion. The nmin fragmentation pathway is a McLafTerty te81TBpptment involving the hydr*n atom in a position with respect to the amke nitrogen. Tbe ion h so formed, which is6 most cmcs the base peak, kxes C&-CNH ...