1: 93 percent / MnO2 / CH2Cl2 / 20 h / Heating 2: 73 percent / hydroxylamine hydrochloride / ethanol; pyridine / 30 h / Heating 3: 17 percent / CO; pentamethylcyclopentadienyl dicarbonyl iron(II) dimer / dioxane / 75 h / 150 °C / 38000 Torr View Scheme

sodium tetrahydroborate; NiII chloride hexahydrate in ethanol T=0°C; 2 h;

ethanol; platinum Hydrogenation;

manganese(IV) oxide in dichloromethane 20 h; Heating;