1: 4-toluenesulfonic acid monohydrate / benzene / 1.5 h / Ambient temperature 2: 80percent aq. acetic acid / 1 h / Ambient temperature 3: 79 percent / SO3-pyridine complex / dimethylformamide / 1.5 h / Ambient temperature 4: 0.1 M sodium methoxide / methanol / 16 h / Ambient temperature 5: H2 / 10percent Pd-C / aq. ethanol / 48 h / 2587.7 Torr View Scheme