1.1: TFA / dioxane; H2O / 11 h / 20 °C 1.2: 70 percent / NaBH4 / ethanol / 2 h / 0 °C 2.1: imidazole / dimethylformamide / 1 h / 20 °C 3.1: 3.76 g / tetrabutylammonium iodide; NaH / dimethylformamide / 3 h / 0 °C 4.1: 72 percent / sodium acetate / PdCl2 / acetic acid; H2O / 3.5 h / 50 °C 5.1: 87 percent / AcOH; TBAF / tetrahydrofuran / 8 h / 20 °C 6.1: H2 / 10 percent Pd/C / acetic acid; ethanol; H2O / 45 h / 20 °C 6.2: 53 percent / HCl / H2O View Scheme

1.1: TFA / dioxane; H2O / 11 h / 20 °C 1.2: 70 percent / NaBH4 / ethanol / 2 h / 0 °C 2.1: imidazole / dimethylformamide / 1 h / 20 °C 3.1: 3.76 g / tetrabutylammonium iodide; NaH / dimethylformamide / 3 h / 0 °C 4.1: 72 percent / sodium acetate / PdCl2 / acetic acid; H2O / 3.5 h / 50 °C 5.1: 87 percent / AcOH; TBAF / tetrahydrofuran / 8 h / 20 °C 6.1: H2 / 10 percent Pd/C / acetic acid; ethanol; H2O / 45 h / 20 °C 6.2: 53 percent / HCl / H2O View Scheme