trans-α,α'-dibromostilbene; tetrakis(triphenylphosphine) palladium(0) in tetrahydrofuran T=0°C;

tetrakis(triphenylphosphine) palladium(0) in tetrahydrofuran byproducts: diphenyl; addn. of the dibromo compd. in THF and the catalyst to a soln. of 1-heptynylzinc chloride in THF under cooling (-75°C), then room temp. (12 h); purifn. by liq. chromy. (Merck H 60 silica gel, hexane);

diisobutylaluminium hydride; Ni(PPh3)4 in tetrahydrofuran; hexane T=-70°C; 2 h; further catalyst; Product distribution;

tetrakis(triphenylphosphine) palladium(0) in tetrahydrofuran T=0°C; 16 h; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

tetrakis(triphenylphosphine) palladium(0) in tetrahydrofuran byproducts: diphenyl; addn. of the dibromo compd. in THF and the catalyst to a soln. of 1-heptynylzinc chloride in THF under cooling (-75°C), then room temp. (12 h); purifn. by liq. chromy. (Merck H 60 silica gel, hexane);