pyridine T=20°C; 0.333333 h;

pyridine in dichloromethane T=20°C;

4-(N,N-dimethlyamino)pyridine; triethylamine in acetonitrile T=20 - 40°C;

1: disulfonyl fluoride; 1,8-diazabicyclo[5.4.0]undec-7-ene; triethylamine tris(hydrogen fluoride) / acetonitrile / 5 h / -15 - 90 °C 2: 2,2-dimethoxy-propane; hydrogenchloride; water / tetrahydrofuran / 3 h / 20 °C 3: hydrogenchloride; water / ethanol / 21 h / 20 °C 4: pyridine / 0.5 h / 20 °C / |Cooling with ice View Scheme

1: disulfonyl fluoride; triethylamine; 1,8-diazabicyclo[5.4.0]undec-7-ene hydrofluoride / acetonitrile / 5 h / 0 - 55 °C 2: 2,2-dimethoxy-propane; water; sulfuric acid / 1,4-dioxane / 16 h / 20 °C / pH 2 - 3 / |Cooling with ice 3: hydrogenchloride; water / ethanol / 18 h / 20 °C 4: pyridine / 0.5 h / 20 °C / |Cooling with ice View Scheme

1: hydrogenchloride; water / ethanol / 21 h / 20 °C 2: pyridine / 0.5 h / 20 °C / |Cooling with ice View Scheme

pyridine optical yield given as percent de;

1.1: 2,2,2-trifluoroethanol; sodium bis(2-methoxyethoxy)aluminium dihydride / toluene; acetic acid n-butyl ester / -20 - -15 °C 1.2: -20 - 20 °C 2.1: tin(IV) chloride / dichloromethane / 20 h / 30 - 80 °C / 1875.19 Torr / |Sealed tube 2.2: 18 - 25 °C View Scheme