1: 81.3 percent / pyridine / 18.5 h 2: 83.8 percent / pyridinium chlorochromate / CH2Cl2 / 2 h 3: 10 percent / trimethyl orthoformate, O2, toluene-p-sulphonic acid / dioxane 4: 39.8 percent / ethanol / 2.5 h / Irradiation 5: 75 percent / H2 / Pd-CaCO3 / pyridine 6: 28.5 mg / potassium hydrogen carbonate, H2O / ethanol / 1 h / Heating 7: 28 mg / HCl / 18 h / Ambient temperature 8: POCl3-pyridine 9: 60percent acetic acid / 91 h / Ambient temperature 10: 1 mg / H2 / Pd-C / dioxane / 6 h View Scheme

1: 83.8 percent / pyridinium chlorochromate / CH2Cl2 / 2 h 2: 10 percent / trimethyl orthoformate, O2, toluene-p-sulphonic acid / dioxane 3: 39.8 percent / ethanol / 2.5 h / Irradiation 4: 75 percent / H2 / Pd-CaCO3 / pyridine 5: 28.5 mg / potassium hydrogen carbonate, H2O / ethanol / 1 h / Heating 6: 28 mg / HCl / 18 h / Ambient temperature 7: POCl3-pyridine 8: 60percent acetic acid / 91 h / Ambient temperature 9: 1 mg / H2 / Pd-C / dioxane / 6 h View Scheme

1: pyridine 2: 10 percent / trimethyl orthoformate, O2, toluene-p-sulphonic acid / dioxane 3: 39.8 percent / ethanol / 2.5 h / Irradiation 4: 75 percent / H2 / Pd-CaCO3 / pyridine 5: 28.5 mg / potassium hydrogen carbonate, H2O / ethanol / 1 h / Heating 6: 28 mg / HCl / 18 h / Ambient temperature 7: POCl3-pyridine 8: 60percent acetic acid / 91 h / Ambient temperature 9: 1 mg / H2 / Pd-C / dioxane / 6 h View Scheme

1: 1.) LiAlH4, 2.) DDQ / 1.) benzene, ether, reflux, 30 min, 2.) dioxane, room temperature, 40 h 2: 81.3 percent / pyridine / 18.5 h 3: 83.8 percent / pyridinium chlorochromate / CH2Cl2 / 2 h 4: 10 percent / trimethyl orthoformate, O2, toluene-p-sulphonic acid / dioxane 5: 39.8 percent / ethanol / 2.5 h / Irradiation 6: 75 percent / H2 / Pd-CaCO3 / pyridine 7: 28.5 mg / potassium hydrogen carbonate, H2O / ethanol / 1 h / Heating 8: 28 mg / HCl / 18 h / Ambient temperature 9: POCl3-pyridine 10: 60percent acetic acid / 91 h / Ambient temperature 11: 1 mg / H2 / Pd-C / dioxane / 6 h View Scheme

1: 10 percent / trimethyl orthoformate, O2, toluene-p-sulphonic acid / dioxane 2: 39.8 percent / ethanol / 2.5 h / Irradiation 3: 75 percent / H2 / Pd-CaCO3 / pyridine 4: 28.5 mg / potassium hydrogen carbonate, H2O / ethanol / 1 h / Heating 5: 28 mg / HCl / 18 h / Ambient temperature 6: POCl3-pyridine 7: 60percent acetic acid / 91 h / Ambient temperature 8: 1 mg / H2 / Pd-C / dioxane / 6 h View Scheme

1: 62 percent / pyridine / 48 h / Ambient temperature 2: 44.5 percent / conc.HCl / methanol / 0.17 h / 100 °C 3: 39.4 percent / aq.KOH / methanol / 3 h / Ambient temperature 4: 1.) LiAlH4, 2.) DDQ / 1.) benzene, ether, reflux, 30 min, 2.) dioxane, room temperature, 40 h 5: 81.3 percent / pyridine / 18.5 h 6: 83.8 percent / pyridinium chlorochromate / CH2Cl2 / 2 h 7: 10 percent / trimethyl orthoformate, O2, toluene-p-sulphonic acid / dioxane 8: 39.8 percent / ethanol / 2.5 h / Irradiation 9: 75 percent / H2 / Pd-CaCO3 / pyridine 10: 28.5 mg / potassium hydrogen carbonate, H2O / ethanol / 1 h / Heating 11: 28 mg / HCl / 18 h / Ambient temperature 12: POCl3-pyridine 13: 60percent acetic acid / 91 h / Ambient temperature 14: 1 mg / H2 / Pd-C / dioxane / 6 h View Scheme

1: 39.4 percent / aq.KOH / methanol / 3 h / Ambient temperature 2: 1.) LiAlH4, 2.) DDQ / 1.) benzene, ether, reflux, 30 min, 2.) dioxane, room temperature, 40 h 3: 81.3 percent / pyridine / 18.5 h 4: 83.8 percent / pyridinium chlorochromate / CH2Cl2 / 2 h 5: 10 percent / trimethyl orthoformate, O2, toluene-p-sulphonic acid / dioxane 6: 39.8 percent / ethanol / 2.5 h / Irradiation 7: 75 percent / H2 / Pd-CaCO3 / pyridine 8: 28.5 mg / potassium hydrogen carbonate, H2O / ethanol / 1 h / Heating 9: 28 mg / HCl / 18 h / Ambient temperature 10: POCl3-pyridine 11: 60percent acetic acid / 91 h / Ambient temperature 12: 1 mg / H2 / Pd-C / dioxane / 6 h View Scheme

1: 44.5 percent / conc.HCl / methanol / 0.17 h / 100 °C 2: 39.4 percent / aq.KOH / methanol / 3 h / Ambient temperature 3: 1.) LiAlH4, 2.) DDQ / 1.) benzene, ether, reflux, 30 min, 2.) dioxane, room temperature, 40 h 4: 81.3 percent / pyridine / 18.5 h 5: 83.8 percent / pyridinium chlorochromate / CH2Cl2 / 2 h 6: 10 percent / trimethyl orthoformate, O2, toluene-p-sulphonic acid / dioxane 7: 39.8 percent / ethanol / 2.5 h / Irradiation 8: 75 percent / H2 / Pd-CaCO3 / pyridine 9: 28.5 mg / potassium hydrogen carbonate, H2O / ethanol / 1 h / Heating 10: 28 mg / HCl / 18 h / Ambient temperature 11: POCl3-pyridine 12: 60percent acetic acid / 91 h / Ambient temperature 13: 1 mg / H2 / Pd-C / dioxane / 6 h View Scheme

hydrogen; palladium on activated charcoal in 1,4-dioxane 6 h;

1: 28 mg / HCl / 18 h / Ambient temperature 2: POCl3-pyridine 3: 60percent acetic acid / 91 h / Ambient temperature 4: 1 mg / H2 / Pd-C / dioxane / 6 h View Scheme