1: pyridine / 16 h / 20 °C 2: p-toluenesulfonic acid / H2O; acetonitrile / 2 h / 20 °C View Scheme

phosphomolybdic acid; silica gel in acetonitrile T=20°C; 0.166667 h;

1.1: sodium hydride / N,N-dimethyl-formamide; mineral oil / 0.5 h / 0 °C / Inert atmosphere 1.2: 0 - 20 °C / Inert atmosphere 2.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 16 h / 20 °C / Inert atmosphere View Scheme

1.1: sodium hydride / N,N-dimethyl-formamide; mineral oil / 0.5 h / 0 °C / Inert atmosphere 1.2: 0 - 20 °C / Inert atmosphere 2.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 16 h / 20 °C / Inert atmosphere 3.1: 1H-imidazole; iodine; triphenylphosphine / toluene / 3 h / 70 °C / Inert atmosphere View Scheme