1: sodium methylate; methanol 2: sodium hydride / N,N-dimethyl-formamide / 12 h / 0 - 20 °C 3: N-iodo-succinimide; water / acetone 4: acetic anhydride; dimethyl sulfoxide / 20 °C View Scheme

1: 51 percent / PPh3, CBr4 / acetonitrile / 0.33 h / Ambient temperature 2: 92 percent / PCC, 3 Angstroem molecular sieves / CH2Cl2 / 1.5 h / Ambient temperature 3: 40 percent / NaBH4 / methanol / 0.5 h / -60 °C 4: 8 percent / TsCl, pyridine / 20 h / 50 °C View Scheme

1: 92 percent / PCC, 3 Angstroem molecular sieves / CH2Cl2 / 1.5 h / Ambient temperature 2: 40 percent / NaBH4 / methanol / 0.5 h / -60 °C 3: 8 percent / TsCl, pyridine / 20 h / 50 °C View Scheme

pyridine T=50°C; 20 h;

1: tetra-(n-butyl)ammonium iodide; sodium hydride / N,N-dimethyl-formamide 2: sulfuric acid; acetic acid / 145 °C 3: acetic anhydride; dimethyl sulfoxide View Scheme

1: tetra-(n-butyl)ammonium iodide; sodium hydride / N,N-dimethyl-formamide 2: sulfuric acid; acetic acid / 145 °C 3: acetic anhydride; dimethyl sulfoxide View Scheme

1.1: sodium hydride / N,N-dimethyl-formamide; mineral oil / 0.5 h / 0 °C / |Inert atmosphere 1.2: 7 h / 20 °C / |Inert atmosphere 2.1: potassium tert-butylate / N,N-dimethyl-formamide / 2 h / 70 °C / |Inert atmosphere 2.2: 0.08 h / |Cooling; |Inert atmosphere 3.1: Dess-Martin periodane / dichloromethane / 1.5 h / 20 °C / |Inert atmosphere View Scheme

1.1: potassium tert-butylate / N,N-dimethyl-formamide / 2 h / 70 °C / |Inert atmosphere 1.2: 0.08 h / |Cooling; |Inert atmosphere 2.1: Dess-Martin periodane / dichloromethane / 1.5 h / 20 °C / |Inert atmosphere View Scheme

1: sulfuric acid; acetic acid / 145 °C 2: acetic anhydride; dimethyl sulfoxide View Scheme