1: DMSO, acetic anhydride 2: NaBH4 / 1.5 h / 0 °C 3: 80 percent / pyridine / 20 h / 60 °C 4: 80 percent / n-Bu4NF 5: 82 percent / p-toluenesulfonic acid / dioxane / 2 h / 23 °C 6: 78 percent / NaOH / acetonitrile; methanol; H2O 7: pyridine, (N,N-dimethylamino)pyrydine / CH2Cl2 / 1 h / 5 °C 8: tertbutylammonium fluoride / tetrahydrofuran / 5 h / 5 °C 9: 41 percent / Dowex 50W x 2-100 / methanol / 1 h / 23 °C 10: 80 percent / sat. NH3 in MeOH / 16 h / 20 °C View Scheme

1: triethylamine; 4-dimethylaminopyridine / CH2Cl2 / 8 h / 20 °C 2: 2-tBuN-2-Et2N-1,3-dimethylperhydro-1,3,2-diazaphosphorine / acetonitrile / 1.5 h 3: tetrabutylammonium fluoride / tetrahydrofuran View Scheme