1: 71.69 percent / PhNCO, Et3N / benzene / Ambient temperature 2: 79 percent / H2, Raney-Ni / acetic acid; methanol; H2O / 3 h 3: 55 percent / Jones reagent / acetone / 0.33 h / 0 °C 4: BF3*Et2O, DMS / CH2Cl2 / 2.5 h / Ambient temperature 5: PTSA / benzene View Scheme