The synthesis of bicyclo [9.3. 1] pentadecatriene skeleton was investigated by employing cyclization reactions using two key precursors bearing acetylene cobalt complex. Cyclization for the synthesis of strained twelve-membered ring was achieved via Nicholas type reaction in reasonable yield. Reductive decomplexation of the dicobalt hexacarbonyl moiety of the cyclization product was achieved with n-Bu3SnH in the presence of a catalytic amount of ...
