1: 97 percent / PtO2 / ethyl acetate / 12 h / 20 °C 2: 80 percent / HCl; H2O / methanol / 12 h / 60 °C 3: 71 percent / DCC / CH2Cl2 / 12 h 4: NH3; H2O / CHCl3; methanol / 12 h / 20 °C 5: H2O2; H2O / 12 h / 20 °C View Scheme