1.1: 98 percent / imidazole / dimethylformamide / 12 h / 20 °C 2.1: BH3*SMe2 / tetrahydrofuran / 10 h / 20 °C 2.2: 70 percent / NaOH; aq. H2O2 / tetrahydrofuran 3.1: 87 percent / MsCl; Et3N / tetrahydrofuran / 3 h / 0 °C 4.1: H2 / Pd/C / methanol / 3 h / 60 °C 5.1: 0.14 g / Dowex 50W-X8; H2O / tetrahydrofuran / Heating View Scheme