1: With oxalyl dichloride; dimethyl sulfoxide in dichloromethane T=-78°C; Swern Oxidation; Inert atmosphere; 2: With triethylamine in dichloromethane T=-78°C; Swern Oxidation; Inert atmosphere;

hydrogenchloride in tetrahydrofuran T=20°C; 5 h;

1.1: POCl3 / 1 h / 70 °C 1.2: 75 percent / 3 h / 10 °C 2.1: 93 percent / p-toluenesulfonic acid hydrate / methanol / 2 h / 20 °C 3.1: Na2CO3; Br2 / -30 - 20 °C 4.1: citric acid; Na2HPO4 / dioxane; H2O / 2 h / 55 °C 5.1: citric acid; Na2HPO4 / dioxane; H2O / 2 h / 75 °C 6.1: H2 / Pd/C / methanol / 0.5 h / atmospheric pressure 7.1: acetyl chloride; methanol / 3 h / 20 °C 8.1: hydrochloric acid / tetrahydrofuran / 5 h / 20 °C View Scheme

1: Na2CO3; Br2 / -30 - 20 °C 2: citric acid; Na2HPO4 / dioxane; H2O / 2 h / 55 °C 3: citric acid; Na2HPO4 / dioxane; H2O / 2 h / 75 °C 4: H2 / Pd/C / methanol / 0.5 h / atmospheric pressure 5: acetyl chloride; methanol / 3 h / 20 °C 6: hydrochloric acid / tetrahydrofuran / 5 h / 20 °C View Scheme

1: H2 / Pd/C / methanol / 0.5 h / atmospheric pressure 2: acetyl chloride; methanol / 3 h / 20 °C 3: hydrochloric acid / tetrahydrofuran / 5 h / 20 °C View Scheme

1: citric acid; Na2HPO4 / dioxane; H2O / 2 h / 75 °C 2: H2 / Pd/C / methanol / 0.5 h / atmospheric pressure 3: acetyl chloride; methanol / 3 h / 20 °C 4: hydrochloric acid / tetrahydrofuran / 5 h / 20 °C View Scheme

1: citric acid; Na2HPO4 / dioxane; H2O / 2 h / 55 °C 2: citric acid; Na2HPO4 / dioxane; H2O / 2 h / 75 °C 3: H2 / Pd/C / methanol / 0.5 h / atmospheric pressure 4: acetyl chloride; methanol / 3 h / 20 °C 5: hydrochloric acid / tetrahydrofuran / 5 h / 20 °C View Scheme

1: acetyl chloride; methanol / 3 h / 20 °C 2: hydrochloric acid / tetrahydrofuran / 5 h / 20 °C View Scheme

1.1: dicobalt octacarbonyl / hexane / 1 h / |Inert atmosphere 1.2: 20 °C / 4500.45 Torr / |Inert atmosphere; |Molecular sieve 2.1: pyridine hydrogenfluoride / tetrahydrofuran / 0 - 20 °C / |Inert atmosphere 3.1: oxalyl dichloride; dimethyl sulfoxide / dichloromethane / -78 °C / |Inert atmosphere 3.2: -78 °C / |Inert atmosphere View Scheme

1.1: pyridine hydrogenfluoride / tetrahydrofuran / 0 - 20 °C / |Inert atmosphere 2.1: oxalyl dichloride; dimethyl sulfoxide / dichloromethane / -78 °C / |Inert atmosphere 2.2: -78 °C / |Inert atmosphere View Scheme