Lawesson's reagent in toluene Heating;

p-benozquinone; dichloro bis(acetonitrile) palladium(II) in 1,4-dioxane T=80°C; 12 h;

tri-n-butyl-tin hydride in benzene T=20°C;

hydrogen iodide in water; acetonitrile T=0 - 20°C;

1.1: n-BuLi / tetrahydrofuran; hexane / 0.5 h / cooling 1.2: 60 percent / hexane; tetrahydrofuran / 0.5 h / 20 °C 2.1: thionyl chloride / 1 h / 65 °C 3.1: 75 percent / triethylamine / CH2Cl2 4.1: 12 percent / benzoquinone / PdCl2(MeCN)2 / dioxane / 12 h / 80 °C View Scheme

1.1: diethyl zinc; trifluoroacetic acid / CH2Cl2; hexane / 20 h / cooling 1.2: 93 percent / CH2Cl2; hexane / 0.5 h / cooling 2.1: n-BuLi / tetrahydrofuran; hexane / 0.5 h / cooling 2.2: 60 percent / hexane; tetrahydrofuran / 0.5 h / 20 °C 3.1: thionyl chloride / 1 h / 65 °C 4.1: 75 percent / triethylamine / CH2Cl2 5.1: 12 percent / benzoquinone / PdCl2(MeCN)2 / dioxane / 12 h / 80 °C View Scheme

1: thionyl chloride / 1 h / 65 °C 2: 75 percent / triethylamine / CH2Cl2 3: 12 percent / benzoquinone / PdCl2(MeCN)2 / dioxane / 12 h / 80 °C View Scheme

1,1,2,2-tetramethylethylene; oxygen in benzene Ambient temperatureIrradiation;

1.1: n-BuLi / diethyl ether; hexane / 1 h / 0 °C 1.2: 65 percent / diethyl ether; hexane / 0 °C 2.1: 69 percent / NaHCO3; I2 / acetonitrile / 0 °C 3.1: 81 percent / n-Bu3SnH / benzene / 20 °C View Scheme

1.1: n-BuLi / diethyl ether; hexane / 1 h / 0 °C 1.2: 65 percent / diethyl ether; hexane / 0 °C 2.1: 69 percent / NaHCO3; I2 / acetonitrile / 0 °C 3.1: 81 percent / n-Bu3SnH / benzene / 20 °C View Scheme