Synthesis of the D2d-Dinoradamantane Derivatives Having Two Coaxially Oriented Unsaturated Centers. 6-Methylene-D2d-dinoradamantan-2-one and D2d-Dinoradamantane-2,6-dione

Article abstract of DOI:10.1021/jo00139a017

From the cyclopentadiene-maleic anhydride adduct was prepared the norbornenecarboxylic acid 22.Treatment of the acid chloride 23 with triethylamine afforded the tetracyclic ketone 24 which was converted into the dinoradamantanecarboxylic acid 25 by a basic ring-opening reaction.The sequence of conversions involving the Cope elimination of the amine oxide derived from the amine 31 provided 6-methylene-D_2d-dinoradamantan-2-one (6) whose OsO4-NaIO4 oxidation eventually yielded D_2d-dinoradamantane-2,6-dione (7) of D₂ symmetry.