SYNTHESIS OF MACROCYCLE OF MACROCYCLES CONTAINING 3-8 CALIX[4]ARENE UNITS - UNEXPECTED GENERATION OF LARGE SUPER-MACROCYCLES

A new class of calixarene-based macrocycles consisting of three to eig ht calix[4]arene subunits has been prepared from starting utyl-25,27-d ihydroxy-26,28-dipropoxycalix[4]arene. The macrocyclization has been a chieved either by direct alkylation with 1,6-dibromohexane in DMF in t he presence of NaH or via appropriate intermediates. Thus, the startin g compound was transformed into bis-calix[4]arenes bearing two bromoal kyl substituents or two hydroxyl groups in positions suitable for furt her cyclization. By the mutual reactions of the above noticed compound s super-macrocycles containing 3, 4, 6, and 8 calix[4]arene subunits c onnected by hexamethylene chains have been prepared and characterized. This is a novel strategy to design a ''macrocycle of macrocycles''. C opyright (C) 1996 Elsevier Science Ltd