A NEW DELTAPHANE AND RIBBON-SHAPED CYCLOP HANES

The reaction of the fourfold functionalized [3.3][3.3]metacyclophane 8 with tosylamide monosodium salt leads to a new deltaphane in quantita tive yield. An X-ray analysis confirms the belt-shaped structure of 3. Moreover, a series 10-15 of well-soluble belt-shaped macrocycles with up to 21 interconnected benzene rings were detected. The intermediate [3.3][3.3]metacyclophane 4 shows remarkably short distances to enclos ed toluene, one toluene molecule acting twice as a pi acceptor and onc e as a pi donor. Competition experiments with benzene demonstrate the dependence of conformational behaviour on the solvent.