1.1: 97 percent / imidazole / dimethylformamide / 18 h / 23 °C 2.1: 66 percent / (saltmen)Mn(N) / CH2Cl2 / 12 h / 23 °C 3.1: 75 percent / silver(I) oxide / tetrahydrofuran / 120 h / 23 °C 4.1: NaOH / methanol; H2O / 7 h / Heating 4.2: methanol / 0.5 h / 0 °C 4.3: 74 percent / acetic acid / tetrahydrofuran; H2O / 1.5 h / 45 °C View Scheme