1.1: triethylamine / dichloromethane / 1 h / 0 - 5 °C 2.1: sodium hydroxide; water / methanol / 40 °C 2.2: pH 2 - 4 3.1: 1,1'-carbonyldiimidazole / ethyl acetate / 3 h / 0 - 30 °C 3.2: 20 - 25 °C 4.1: potassium carbonate / acetonitrile / 70 °C 4.2: 15 h / 0 - 25 °C 5.1: lithium hexamethyldisilazane / tetrahydrofuran / 1 h / -20 - -10 °C 6.1: hydrogenchloride; water / acetonitrile / 15 h / 40 °C 7.1: sodium hydroxide; water / ethanol / 16 h / 20 - 25 °C View Scheme

1.1: sodium hydrogencarbonate; sodium hypochlorite; potassium bromide; 4-hydroxy-2,2,6,6-tetramethyl piperidinyloxy, free radical / ethyl acetate; water / 1 h / -10 - 5 °C / Inert atmosphere 2.1: sodium hexamethyldisilazane / tetrahydrofuran / 0.33 h / -78 °C / Inert atmosphere 2.2: 21 h / -35 - 0 °C View Scheme

1: 77 percent / oxalyl chloride; DMSO; Et3N / CH2Cl2 / -60 - 20 °C 2: 95 percent / KF / propan-2-ol / 5 h / 20 °C 3: 4-dimethylaminopyridine / diethyl ether / 1 h / 20 °C 4: 92 percent / NaBH4 / ethanol / 1 h / 20 °C 5: 0.3 g / H2 / 10 percent Pd/C / methanol / 2 h / 20 °C View Scheme

1: 95 percent / NEt3 / CH2Cl2 2: 90 percent / dimethylsulfoxide View Scheme

Swern oxidation; (further oxidizing agents);

dimethyl sulfoxide; triethylamine in dichloromethane

in 1-methyl-pyrrolidin-2-one

pyridine in dichloromethane T=20°C; 0.5 h;