1: O2, Bengalrosa B / CH2Cl2 / 0.17 h / 25 °C / Irradiation 2: triethylamine / CH2Cl2 / 0.08 h / Ambient temperature 3: 64 percent / 16 h / 40 °C 4: 86 percent / pyridiniumchlorochromate, NaAc*3H2O / CH2Cl2 / 0.42 h / Ambient temperature 5: 2.) CH3COOH, CF3COOH, H2O / 1.) CH2Cl2, room temp., 30 min, irradiation; 2.) THF, 15 degC, 24h 6: 95 percent / 1.5percent methanolic HCl / 16 h / Ambient temperature View Scheme