1: pyridinium p-toluenesulfonate / toluene / 0.75 h / 70 °C 2: 90 percent / copper bronze / dimethylformamide / 22 h / 108 °C 3: 95 percent / magnesium monoperoxyphthalate / H2O; acetonitrile / 2 h / 50 °C 4: 95 percent / imidazole / dimethylformamide / 2 h / 25 °C 5: 97 percent / diisobutylaluminum hydride / toluene / 1 h / -70 °C 6: 1) Mg 7: 94 percent / oxalic acid / methanol / 20 h / 23 °C View Scheme

1: pyridinium p-toluenesulfonate / toluene / 0.75 h / 70 °C 2: 90 percent / copper bronze / dimethylformamide / 22 h / 108 °C 3: 95 percent / magnesium monoperoxyphthalate / H2O; acetonitrile / 2 h / 50 °C 4: 95 percent / imidazole / dimethylformamide / 2 h / 25 °C 5: 97 percent / diisobutylaluminum hydride / toluene / 1 h / -70 °C 6: 1) Mg View Scheme