Synthesis of [0]Orthocyclo[2]orthocyclo[0](1,1′)ferrocenophane and [0]Paracyclo[0](1,1′)ferrocenophane

Abstract syn- and anti-[0]Orthocyclo[2]orthocyclo[0](1,1′)ferrocenophan-7-enes were synthesized via an intramolecular reductive coupling of 1,1′-bis(o-formylphenyl)ferrocene with low valent titanium reagents, syn- and anti-[0]Orthocyclo[2]orthocyclo[0](1,1′)ferrocenophanes and [0]paracyclo[2]paracyclo[0](1,1′)ferrocenophane were prepared by the reaction of 1,1′-bis[o-(bromomethyl)phenyl]ferrocene and 1,1′-bis[p-(bromomethyl)phenyl]ferrocene with butyllithium. The transannular π-electronic interactions between two aromatic rings in these compounds were examined on the basis of the NMR and electronic spectra.