ORTHOCYCLOPHANES .1. SYNTHESIS AND CHARACTERIZATION OF [14]ORTHOCYCLOPHANE AND [15]ORTHOCYCLOPHANE AND BICYCLIC BISCYCLOPHANES

[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. Bicyclic biscyclophanes were also prepared from the cyclic diketones giving rise to a new family of cyclophanes. Treatment of 23 and 29, respectively, with McMurry or Clemmensen reagents gave rise to intramolecular olefination to provide bicyclic biscyclophanes 24 and 30. Pd-catalyzed hydrogenation of 24 and 30 also gave 4 and 5. The benzylic positions of the cycloheptatriene moieties in 24 and 30 were very susceptible to oxidation to give ketones 26 and 32.