1: Li2CuCl4 / tetrahydrofuran / 0.5 h / 25 °C 2: pyridinium p-toluenesulfonate / ethanol / 3.5 h / 40 °C 3: 1.) sodium hydride / 1.) DME, 50 deg C to 55 deg C, 2 h, 2.) toluene, -10 deg C, 2 h 4: 1.) n-BuLi / 1.) THF, hexane, -78 deg C, 0.5 h, 2.) -78 deg C, 2 h View Scheme

1.1: n-butyllithium / tetrahydrofuran; hexane / 0 °C / Inert atmosphere 1.2: 0 - 20 °C / Inert atmosphere 1.3: 20 °C / Inert atmosphere 2.1: water; sodium hydroxide / methanol View Scheme

1.1: n-butyllithium / tetrahydrofuran; hexane / 2 h / -78 °C 1.2: 16 h / -78 - 20 °C 2.1: potassium carbonate / tetrahydrofuran; methanol / 18 h / 0 - 20 °C View Scheme

1.1: n-butyllithium / tetrahydrofuran; hexane / 0 °C / Inert atmosphere 1.2: 0 - 20 °C / Inert atmosphere 1.3: 20 °C / Inert atmosphere 2.1: water; sodium hydroxide / methanol 3.1: bis-triphenylphosphine-palladium(II) chloride; diethylamine; copper(l) chloride / 0 - 20 °C / Inert atmosphere 4.1: oxalyl dichloride; dimethyl sulfoxide / dichloromethane / -78 °C / Inert atmosphere 4.2: -78 - 20 °C / Inert atmosphere 5.1: indium trifluoromethanesulfonate; butan-1-ol / dichloromethane / 3 h / 20 °C / Inert atmosphere View Scheme