STRUCTURALLY-UNUSUAL CALIX[4]ARENE DERIVATIVES GENERATED BY INTRAMOLECULAR AND INTERMOLECULAR MCMURRY REACTIONS

A new class of calix[4]arene derivatives with highly strained structur es has been synthesized by intramolecular reductive dimerization of ap propriate formyl groups in the presence of low-valent titanium agents (so-called McMurry reaction). New derivatives possessed very interesti ng molecular structures with upper rims intramolecularly connected by a CH=CH bond and are immobilized either in cone or in 1,3-alternate co nformation. The cage compound with inner space perfectly closed by fou r aromatic units has been obtained from tetraformyl derivative in 1,3- alternate conformation. Intermolecular reductive coupling of two monof ormylcalix[4]arenes has a yielded a bis-calixarene derivative which wa s found to behave as a good host molecule for quaternary ammonium salt s.