bis(1,5-cyclooctadiene)nickel (0); 1,3-bis-(diphenylphosphino)propane in toluene for 24 h at 50°C under an allene atmosphere; filtered, concd., chromd. (preparative GPC);

1: 73 percent / Pd(Ph3)4; CuCl; CuCl2 / dimethylsulfoxide / 0.8 h / 40 °C 2: 92 percent / AcOH; Bu4NF / tetrahydrofuran / 45 h / 20 °C View Scheme