1.1: H2 / Pd/C / methanol / 24 h / 20 °C 1.2: H2; hydrochloric acid / Pd/C / methanol / 36 h / 20 °C 1.3: 74 percent / AcOH / toluene / 16 h / 80 °C 2.1: Et3N / tetrahydrofuran / 16 h / 20 °C 3.1: 78 percent / 1,2-dimethoxy-ethane / 60 h / 50 °C 4.1: tetrabutylammonium bromide; KOH / tetrahydrofuran / 0.5 h / 0 °C 4.2: 98 percent / tetrahydrofuran / 5 h / 20 °C 5.1: 90 percent / HCl / toluene / 1.5 h / 0 - 20 °C View Scheme

1.1: H2 / Pd/C / methanol / 24 h / 20 °C 1.2: H2; hydrochloric acid / Pd/C / methanol / 36 h / 20 °C 1.3: 74 percent / AcOH / toluene / 16 h / 80 °C 2.1: Et3N / tetrahydrofuran / 16 h / 20 °C 3.1: 78 percent / 1,2-dimethoxy-ethane / 60 h / 50 °C View Scheme