Orthocyclophanes. 1. Synthesis and characterization of [14]- and [15]orthocyclophanes and bicyclic biscyclophanes

Abstract

[1 4 ]- and [1 5 ]orthocyclophanes have been designed, synthesized and characterized. Dimetalation of bis(2-bromophenyl)methane (14) to the corresponding dilithio reagent 21, followed by reaction with aromatic dialdehydes bis(2-formylphenyl)methane (20) and 1,2-bis(2-formylbenzyl)benzene (27), gave cyclic diols 22 and 28, respectively. Oxidation of the diols with PCC to the corresponding cyclic diketones 23 and 29, followed by palladium-catalyzed reduction, afforded [1 4 ]- and [1 5 ]orthocyclophanes, 4 and 5