Synthesis and phototransformations of novel styryl-substituted furo-benzobicyclo[3.2.1]octadiene derivatives

Novel cis- and trans-(o-H/Me/vinyl) substituted styryl furo-benzobicyclo3.2.1]octadiene derivatives (7a,b, 8) were prepared and transformed to the novel naphthofuran derivatives of benzobicyclo3.2.1]octadiene (6a,b) and novel phenanthrene-benzobicyclo3.2.1]octadiene derivative (11) by photochemical electrocyclic ring closure in the presence of iodine and by intramolecular photoinduced 4+2] cycloaddition, respectively. These novel annelated bicyclo3.2.1]octadiene derivatives (6a,b, 11) are especially interesting for their rigid methano-bridged junction of two aromatic units at defined geometrical arrangement and thereby as potentials for molecular clips.