1: [(2,5-dibromobenzene-1,4-diyl)diethyne-2,1-diyl]-bis(trimethylsilane) With n-butyllithium in diethyl ether; hexane T=-78°C; 1 h; 2: tri-isopropylsylil trifluoromethane sulfonate in diethyl ether; hexane T=-78 - 20°C;

methanol; potassium carbonate in tetrahydrofuran T=20°C; 5 h;