1: 1,1-dibromo-4-(triisopropylsilyl)but-1-en-3-yne With lithium diisopropyl amide in tetrahydrofuran; hexane T=-78°C; 1 h; 2: chloro-trimethyl-silane in tetrahydrofuran; hexane T=-78 - 20°C;

1: AlCl3, aluminium chloride / dichloromethane / 0 °C / Inert atmosphere 2: carbon tetrabromide; triphenylphosphine / dichloromethane / Inert atmosphere 3: n-butyllithium / hexane / -78 - -20 °C / Inert atmosphere View Scheme

1: K2CO3 / tetrahydrofuran; methanol 2: 96 percent / CuI; triethylamine / Pd(PPh3)4 / 50 °C View Scheme