1.1: NaH / tetrahydrofuran / 1 h / 20 °C 1.2: 30 percent / tetrahydrofuran / 3 h / Heating 2.1: NH2OH*HCl; MeONa / methanol / 48 h / 20 °C 3.1: HCO2H / 10 h / 20 °C 4.1: 43 percent / H2; Ac2O; AcOH / 10 percent Pd/C View Scheme