A new route to the asymmetric cylindrical macrotricyclic ligands

New asymmeric cylindrical macrotricyclic ligands have been prepared containing two diaza‐12‐crown‐4 units connected by diethyleneoxy or triethyleneoxy and meta ‐ or para ‐xylylene bridges, 2‐4 . These materials were prepared in three steps by first treating 6‐tosyl‐6‐aza‐3,9‐dioxa‐1,11‐undecanediyl ditosylate with 3‐oxa‐1,5‐pentanediamine or 3,6‐dioxa‐1,8‐octanediamine to form ditosyl‐substituted bis(diaza‐12‐crown‐4)s connected by a diethyleneoxy or triethylencoxy bridge. These latter compounds were detosylated and treated with either para ‐ or meta ‐α,α'‐dibromoxylene to give new asymmetric cylindrical macrotricycles 2‐4 . The solid state structure of one of these ligands, 3 , has been determined by X‐ray diffraction methods.