oxalyl dichloride; dimethyl sulfoxide; triethylamine in dichloromethane T=-65 - 20°C; 0.5 h;

1.1: Cp2ZrCl2 / hexane / 76 h / 45 °C 1.2: 92 percent / iodine / hexane / 2 h / 20 °C 2.1: 93 percent / imidazole / dimethylformamide / 5 h / 0 - 20 °C 3.1: 1,2-dibromoethane; magesium; iodine / zinc chloride / tetrahydrofuran / 2 h / 45 °C 3.2: 84 percent / (PPh3)4Pd / tetrahydrofuran / 24 h / 20 °C 4.1: 85 percent / tetra-n-butylammonium fluoride trihydrate / tetrahydrofuran / 4 h / 20 °C 5.1: 75 percent / oxalyl chloride; DMSO; triethylamine / CH2Cl2 / 0.5 h / -65 - 20 °C View Scheme

1.1: 93 percent / sodium hydride; n-butyllithium / tetrahydrofuran; hexane / 4 h / -70 - 20 °C 2.1: 91 percent / triethylamine / CH2Cl2 / -10 °C 3.1: 88 percent / lithium bromide / acetone / 72 h / 40 °C 4.1: 1,2-dibromoethane; magesium; iodine / zinc chloride / tetrahydrofuran / 2 h / 45 °C 4.2: 84 percent / (PPh3)4Pd / tetrahydrofuran / 24 h / 20 °C 5.1: 85 percent / tetra-n-butylammonium fluoride trihydrate / tetrahydrofuran / 4 h / 20 °C 6.1: 75 percent / oxalyl chloride; DMSO; triethylamine / CH2Cl2 / 0.5 h / -65 - 20 °C View Scheme

1.1: 91 percent / triethylamine / CH2Cl2 / -10 °C 2.1: 88 percent / lithium bromide / acetone / 72 h / 40 °C 3.1: 1,2-dibromoethane; magesium; iodine / zinc chloride / tetrahydrofuran / 2 h / 45 °C 3.2: 84 percent / (PPh3)4Pd / tetrahydrofuran / 24 h / 20 °C 4.1: 85 percent / tetra-n-butylammonium fluoride trihydrate / tetrahydrofuran / 4 h / 20 °C 5.1: 75 percent / oxalyl chloride; DMSO; triethylamine / CH2Cl2 / 0.5 h / -65 - 20 °C View Scheme

1.1: 88 percent / lithium bromide / acetone / 72 h / 40 °C 2.1: 1,2-dibromoethane; magesium; iodine / zinc chloride / tetrahydrofuran / 2 h / 45 °C 2.2: 84 percent / (PPh3)4Pd / tetrahydrofuran / 24 h / 20 °C 3.1: 85 percent / tetra-n-butylammonium fluoride trihydrate / tetrahydrofuran / 4 h / 20 °C 4.1: 75 percent / oxalyl chloride; DMSO; triethylamine / CH2Cl2 / 0.5 h / -65 - 20 °C View Scheme

1.1: 1,2-dibromoethane; magesium; iodine / zinc chloride / tetrahydrofuran / 2 h / 45 °C 1.2: 84 percent / (PPh3)4Pd / tetrahydrofuran / 24 h / 20 °C 2.1: 85 percent / tetra-n-butylammonium fluoride trihydrate / tetrahydrofuran / 4 h / 20 °C 3.1: 75 percent / oxalyl chloride; DMSO; triethylamine / CH2Cl2 / 0.5 h / -65 - 20 °C View Scheme

1.1: 93 percent / imidazole / dimethylformamide / 5 h / 0 - 20 °C 2.1: 1,2-dibromoethane; magesium; iodine / zinc chloride / tetrahydrofuran / 2 h / 45 °C 2.2: 84 percent / (PPh3)4Pd / tetrahydrofuran / 24 h / 20 °C 3.1: 85 percent / tetra-n-butylammonium fluoride trihydrate / tetrahydrofuran / 4 h / 20 °C 4.1: 75 percent / oxalyl chloride; DMSO; triethylamine / CH2Cl2 / 0.5 h / -65 - 20 °C View Scheme

1.1: 1,2-dibromoethane; magesium; iodine / zinc chloride / tetrahydrofuran / 2 h / 45 °C 1.2: 84 percent / (PPh3)4Pd / tetrahydrofuran / 24 h / 20 °C 2.1: 85 percent / tetra-n-butylammonium fluoride trihydrate / tetrahydrofuran / 4 h / 20 °C 3.1: 75 percent / oxalyl chloride; DMSO; triethylamine / CH2Cl2 / 0.5 h / -65 - 20 °C View Scheme

1: 85 percent / tetra-n-butylammonium fluoride trihydrate / tetrahydrofuran / 4 h / 20 °C 2: 75 percent / oxalyl chloride; DMSO; triethylamine / CH2Cl2 / 0.5 h / -65 - 20 °C View Scheme

1: propargyl bromide With iodine; magnesium; ethylene dibromide; mercury dichloride in tetrahydrofuran T=5 - 15°C; 1 h; 2: (E)-4-methylundec-4-en-10-yn-1-al in tetrahydrofuran T=20°C; 1 h;