1: 96 percent / N2O3 / acetic acid / 1 h / 15 °C 2: 55 percent / 1,2-dimethoxy-ethane / 1 h / Heating 3: 75 percent / 15percent H2SO4 / 6 h / Heating View Scheme

1: 68 percent / KMnO4, H2SO4 / aq. acetic acid / 6 h / 10 - 15 °C 2: 1.) 8 N HCl, 2.) Et3N / 1.) reflux, 12 h, 2.) 80percent aq. EtOH View Scheme

1: H2O / 6 h / 95 °C 2: Et3SiH, CF3CO2H / CHCl3 / 4 h / Ambient temperature 3: 84 percent / a) 8 N aq. HCl, b) 12 N aq. HCl / Heating; a) 4 h, b) 6 h View Scheme