Synthesis of tetramers of 1,3-adamantane derivatives

Novel tetramers of 1,3-adamantane and 5,7-dibutyl-1,3-adamantane were synthesized by the coupling reaction of 3-bromo-1,1′-biadamantane or 3-bromo-5,5′,7,7′-tetrabutyl-1,1′-biadamantane with sodium in n-octane or with magnesium in diethyl ether. Although the former 1,3-adamantane tetramer showed poor solubility in organic solvents, the latter tetrameric 5,7-dibutyl-1,3-adamantane was readily soluble in THF, chloroform and benzene and was successfully characterized by NMR, IR, SEC and elemental analyses.