1.1: 1H-imidazole; 4-(N,N-dimethlyamino)pyridine / dichloromethane / 4 h / 0 - 25 °C / Inert atmosphere 2.1: pyridinium p-toluenesulfonate / ethanol / 1 h / 60 °C 3.1: 1-hydroxy-3H-benz[d][1,2]iodoxole-1,3-dione / dichloromethane; dimethyl sulfoxide / 0.5 h / 20 °C / Inert atmosphere 4.1: magnesium / tetrahydrofuran / 0.5 h / 20 - 25 °C / Inert atmosphere 4.2: 1 h / Inert atmosphere 5.1: pyridinium p-toluenesulfonate / dichloromethane / 0.5 h / 20 °C / Inert atmosphere 6.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 5 h / 0 - 20 °C / Inert atmosphere 7.1: triphenylphosphine; diethylazodicarboxylate / diethyl ether; benzene / 14 h / 20 °C 8.1: pyridinium p-toluenesulfonate / ethanol / 1 h / 60 °C 9.1: RuCl2(tricyclohexylphosphine)2(benzylidene) / toluene / 23 h / 80 °C / Inert atmosphere 10.1: 1-hydroxy-3H-benz[d][1,2]iodoxole-1,3-dione / dichloromethane; dimethyl sulfoxide / 0.5 h / 20 °C / Inert atmosphere 11.1: aluminium(III) iodide; tetra-(n-butyl)ammonium iodide / benzene / 10 °C View Scheme

1: 90 percent / Dowex-50X / methanol 2: AgCO3/Celite View Scheme

Dowex-50X in methanol

phosphoric acid T=200°C;