NOVEL SPHERAND-TYPE CALIXARENES - SYNTHESIS, CONFORMATIONAL STUDIES, AND ISOMER SEPARATION

The novel macrocyclic compounds hexahydroxy[1.0.1.0.1.0]-6b and octahy droxy[1.0.1.0.1.0.1.0]metacyclophane 6c have been prepared in 50-70% y ield by base-catalyzed condensation of 5,5'-di-tert-butyl-2,2'-dihydro xybiphenyl (5) with formaldehyde in xylene. The conformations of trime r 6b and tetramer 6 c have been evaluated from their dynamic H-1-NMR s pectra. Methylation of the hydroxyl groups of 6b and 6c with Mel gives the corresponding methoxy[1n]metabiphenylophanes 7b and 7c in good yi elds. The metacyclophane 7b has been found to consist of two isomers, out of which one was separated pure. The structural characterization o f these products is discussed.