1: iodobenzene With n-butyllithium in tetrahydrofuran T=-78 - -40°C; 2: With zinc dibromide in tetrahydrofuran T=-40°C; 3: Ethyl 2-methyl-3-iodo-3-butenoate With tetrakis(triphenylphosphine) palladium(0) in tetrahydrofuran Sonogashira reaction; 6 h;