indium tribromide in dichloromethane T=20°C; 1 h;

1: anhydrous 1-octyne With n-butyllithium in tetrahydrofuran; hexane T=-78 - 20°C; Inert atmosphere; 2: With zinc(II) chloride in tetrahydrofuran; diethyl ether; hexane T=-78 - 0°C; Inert atmosphere; 3: octanoic acid chloride in tetrahydrofuran; diethyl ether; hexane T=0°C; 6 h; Inert atmosphere;

Yield given. Multistep reaction;