1.1: pyridine; oxygen; ozone / dichloromethane / 3 h / -78 °C 1.2: 0.5 h / -78 °C 2.1: lithium aluminium tetrahydride / tetrahydrofuran / 2.5 h / 0 - 45 °C / Inert atmosphere 3.1: 4-(N,N-dimethlyamino)pyridine / dichloromethane / 3.5 h / 0 °C / Inert atmosphere 4.1: magnesium / tetrahydrofuran / 0.17 h / 50 °C / Inert atmosphere 4.2: 1 h / 0 - 20 °C / Inert atmosphere 5.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 10 h / 0 - 20 °C / Inert atmosphere 6.1: 1,4-dioxane / Irradiation 6.2: 100 °C View Scheme