1: zinc bromide / CH2Cl2 / 20 °C 2: 84 percent / potassium carbonate, potassium iodide / acetone / 20 h / Heating View Scheme

1.1: tert.-butyl lithium / tetrahydrofuran; pentane / 0.08 h / -78 °C / Inert atmosphere 1.2: 0.17 h / -78 °C / Inert atmosphere 1.3: -78 °C / Inert atmosphere 2.1: 1-hydroxy-3H-benz[d][1,2]iodoxole-1,3-dione / dimethyl sulfoxide / 23 h / 20 °C / Inert atmosphere 3.1: n-butyllithium; N,N,N',N,-tetramethylethylenediamine / tetrahydrofuran; hexane / 0.05 h / -98 °C / Inert atmosphere 3.2: 2 h / -98 - -60 °C / Inert atmosphere 3.3: Inert atmosphere 4.1: Cl2Ni(1,2-bis(diphenylphosphino)ethane); 1,1-dimethylethylmagnesium chloride / tetrahydrofuran; dichloromethane / 20 °C / Inert atmosphere 4.2: 20 °C / Inert atmosphere 5.1: diisopropyl-carbodiimide / dichloromethane / 24 h / 20 °C / Inert atmosphere 6.1: titanium(IV) isopropylate; n-butyllithium / tetrahydrofuran; hexane / 2 h / -78 - 50 °C / Inert atmosphere 6.2: Inert atmosphere 7.1: hydrogenchloride; water / tetrahydrofuran / 15 h / 20 °C View Scheme

1: zinc bromide / CH2Cl2 / 20 °C 2: 51 percent / zinc amalgam, concentrated hydrochloric acid / ethanol / 2.5 h / Heating View Scheme

zinc dibromide in dichloromethane T=20°C;

N-ethyl-N,N-diisopropylamine in dichloromethane T=20°C; 5 h; Inert atmosphere;

1: zinc bromide / CH2Cl2 / 20 °C 2: 23 percent / potassium carbonate, potassium iodide / acetone / 65 h / Heating 3: 91 percent / H2 / Lindlar catalyst / ethyl acetate / 20 °C 4: 86 percent / 0.1 h / 135 °C 5: 83 percent / potassium carbonate, potassium iodide / acetone / 16 h / Heating 6: 63 percent / 1.) n-butyl-lithium / hexane; tetrahydrofuran / 1.) 20 min, 2.) 1.5 h 7: 46 percent / sodium, n-butanol / Heating View Scheme