1.1: dipyridinium dichromate / N,N-dimethyl-formamide / 12 h / 20 °C 2.1: hydrazine hydrate / ethylene glycol / 12 h / 165 °C 3.1: sodium hydride / tetrahydrofuran; paraffin oil (nujol) / 0.17 h / 0 °C 3.2: 12 h / 20 °C View Scheme

1: dipyridinium dichromate / N,N-dimethyl-formamide / 12 h / 20 °C 2: hydrazine hydrate / ethylene glycol / 12 h / 165 °C View Scheme

chromium(VI) oxide; sulfuric acid in water; acetone T=0°C; 0.5 h;

1.1: dipyridinium dichromate / N,N-dimethyl-formamide / 12 h / 20 °C 2.1: hydrazine hydrate / ethylene glycol / 12 h / 165 °C 3.1: sodium hydride / tetrahydrofuran; paraffin oil (nujol) / 0.17 h / 0 °C 3.2: 12 h / 20 °C 4.1: potassium acetate / dichloro(1,1'-bis(diphenylphosphanyl)ferrocene)palladium(II) dichloromethane adduct / 1,4-dioxane / 12.5 h / 80 °C / Inert atmosphere View Scheme

1: dipyridinium dichromate / N,N-dimethyl-formamide / 12 h / 20 °C 2: hydrazine hydrate / ethylene glycol / 12 h / 165 °C 3: potassium acetate / dichloro(1,1'-bis(diphenylphosphanyl)ferrocene)palladium(II) dichloromethane adduct / dichloromethane; 1,4-dioxane / 12.5 h / 80 °C / Inert atmosphere View Scheme

1.1: dipyridinium dichromate / N,N-dimethyl-formamide / 12 h / 20 °C 2.1: hydrazine hydrate / ethylene glycol / 12 h / 165 °C 3.1: sodium hydride / tetrahydrofuran; paraffin oil (nujol) / 0.17 h / 0 °C 3.2: 12 h / 20 °C View Scheme