1: 96 percent / acetonitrile / 20 h / Heating 2: NaBH4 / methanol / 1 h / -10 °C 3: HgCl2 / acetonitrile; H2O / 0.25 h 4: NaCNBH3, 1 M HCl, 3-Angstroem molecular sieves / methanol / 112 h / Ambient temperature View Scheme

1: 96 percent / acetonitrile / 20 h / Heating 2: NaBH4 / methanol / 1 h / -10 °C 3: HgCl2 / acetonitrile; H2O / 0.25 h 4: NaCNBH3, 1 M HCl, 3-Angstroem molecular sieves / methanol / 112 h / Ambient temperature 5: 86 percent / trifluoroacetic acid / 1 h / Ambient temperature View Scheme

1: 96 percent / acetonitrile / 20 h / Heating 2: NaBH4 / methanol / 1 h / -10 °C 3: HgCl2 / acetonitrile; H2O / 0.25 h 4: NaCNBH3, 1 M HCl, 3-Angstroem molecular sieves / methanol / 112 h / Ambient temperature 5: 86 percent / trifluoroacetic acid / 1 h / Ambient temperature 6: 48 percent / 1-hydroxybenzotriazole hydrate, dicyclohexylcarbodiimide, N-ethylmorpholine / tetrahydrofuran / 64 h / Ambient temperature 7: H2 / 10percent Pd/C / ethanol / 16 h 8: 1-hydroxybenzotriazole hydrate, dicyclohexylcarbodiimide, N-ethylmorpholine / tetrahydrofuran / 16 h / Ambient temperature View Scheme

1: 96 percent / acetonitrile / 20 h / Heating 2: NaBH4 / methanol / 1 h / -10 °C 3: HgCl2 / acetonitrile; H2O / 0.25 h 4: NaCNBH3, 1 M HCl, 3-Angstroem molecular sieves / methanol / 112 h / Ambient temperature 5: 86 percent / trifluoroacetic acid / 1 h / Ambient temperature 6: 48 percent / 1-hydroxybenzotriazole hydrate, dicyclohexylcarbodiimide, N-ethylmorpholine / tetrahydrofuran / 64 h / Ambient temperature View Scheme