1: With methanesulfonic acid; potassium iodide in 1-methyl-pyrrolidin-2-one T=85°C; 7 h; 2: With sodium hydroxide in 1-methyl-pyrrolidin-2-one; water; ethyl acetate

1: With triphenyl phosphite; N-iodo-succinimide in acetonitrile T=5 - 80°C; 8 h; 2: With sodium hydroxide in water; acetonitrile T=60°C; 2 h;

1: dipotassium hydrogenphosphate / dichloromethane / 1 h / 20 °C 2: sodium hydride / N,N-dimethyl-formamide / 0.5 h / 0 °C 3: trichlorophosphate / 1,2-dichloro-ethane / 8 h / 60 °C 4: potassium tert-butylate / 2-methyl tetrahydrofuran / 9 h / Inert atmosphere; Reflux 5: pyridine / dichloromethane / 1 h / -78 °C 6: dimethylsulfone; potassium iodide / N,N-dimethyl-formamide / 1.5 h / 85 °C View Scheme

1: sodium hydride / N,N-dimethyl-formamide / 0.5 h / 0 °C 2: trichlorophosphate / 1,2-dichloro-ethane / 8 h / 60 °C 3: potassium tert-butylate / 2-methyl tetrahydrofuran / 9 h / Inert atmosphere; Reflux 4: pyridine / dichloromethane / 1 h / -78 °C 5: dimethylsulfone; potassium iodide / N,N-dimethyl-formamide / 1.5 h / 85 °C View Scheme

1: trichlorophosphate / 1,2-dichloro-ethane / 8 h / 60 °C 2: potassium tert-butylate / 2-methyl tetrahydrofuran / 9 h / Inert atmosphere; Reflux 3: pyridine / dichloromethane / 1 h / -78 °C 4: dimethylsulfone; potassium iodide / N,N-dimethyl-formamide / 1.5 h / 85 °C View Scheme

1.1: sodium hydroxide / 2-methyl tetrahydrofuran; water 1.2: 8 h / Reflux 2.1: potassium tert-butylate / 2-methyl tetrahydrofuran / 9 h / Inert atmosphere; Reflux 3.1: pyridine / dichloromethane / 1 h / -78 °C 4.1: dimethylsulfone; potassium iodide / N,N-dimethyl-formamide / 1.5 h / 85 °C View Scheme

1: potassium tert-butylate / 2-methyl tetrahydrofuran / 9 h / Inert atmosphere; Reflux 2: pyridine / dichloromethane / 1 h / -78 °C 3: dimethylsulfone; potassium iodide / N,N-dimethyl-formamide / 1.5 h / 85 °C View Scheme