1.1: 83 percent / NiCl2*6H2O / Heating 2.1: 87 percent / NaIO4 / methanol; H2O / 2 h / 0 - 20 °C 3.1: 88 percent / NaOH / methanol / 0 - 20 °C 4.1: DCC; 1-hydroxypyridine-2-thione / CH2Cl2 / 3 h / 0 °C 4.2: 24 percent / CH2Cl2 / 60 h / 0 °C / UV-irradiation 5.1: Bu3SnH; AIBN / benzene / 60 h / 80 °C View Scheme