NOVEL BENZENE-BRIDGED MACROBICYCLIC AND MACROTRICYCLIC POLYETHERS

Novel three-dimensional benzene-bridged macrobicyclic polyether 1 and macrotricyclic polyether 2 have been prepared. Macrobicyclic triply br idged cyclophane crown compound 1 was synthesized by a tripode-tripode coupling of 5-tris[7'-(tosyloxy)-2',5'-dioxa-1'-heptyl]benzene (19) w ith 1,3,5-tris(hydroxymethyl)benzene (5). Macrotricyclic quadruply bri dged cyclophane crown ether 2 was obtained by a quadrupode-quadrupode coupling of -tetrakis(7'-tosyloxy-2,5'-dioxa-1'-heptyl)benzene (20) wi th 1,2,4,5-tetrakis(hydroxymethyl)benzene (6). These ligands could hav e suitable rigidity and cavity sizes for the coordination of metal cat ions. They appear to have selectivities for cesium over sodium and lea d ions, and 2 shows a log K value of 3.50 for interaction with cesium ion in 80% CH3OH/20% water (v/v). Macrotricyclic polyether 2 containin g benzene bridgeheads is a new type of ligand, and its structure was c onfirmed by an X-ray crystallographic study.