1: With hydrogen bromide; sodium nitrite in water T=0°C; 0.166667 h; 2: With copper(I) bromide in water T=0°C; Sandmeyer reaction; 2.66667 h; Reflux;

1.1: HNO2 1.2: copper(I) bromide; HBr 2.1: 85 percent / copper(I) iodide; potassium carbonate; (+/-)-trans-1,2-diaminocyclohexane / dioxane / 15 h / 110 °C 3.1: 80 percent / pyridinium p-toluenesulfonate / ethanol / 0.5 h / Heating 4.1: triethylamine / CH2Cl2 / 1 h / 0 - 25 °C View Scheme

1.1: NaI; Na2CO3 / dimethylformamide / 65 °C 2.1: aq. NaHCO3 / acetone 3.1: 95 percent / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - -60 °C 4.1: nitrosobenzene; D-proline / acetonitrile / 24 h / -20 °C 4.2: NaBH4 / methanol 4.3: 86 percent / CuSO4 / methanol 5.1: 96 percent / sodium hydride / tetrahydrofuran / 0 °C View Scheme

Multistep reaction;

1.1: NaI; Na2CO3 / dimethylformamide / 65 °C 2.1: aq. NaHCO3 / acetone 3.1: 95 percent / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - -60 °C 4.1: nitrosobenzene; D-proline / acetonitrile / 24 h / -20 °C 4.2: NaBH4 / methanol 4.3: 86 percent / CuSO4 / methanol 5.1: 96 percent / sodium hydride / tetrahydrofuran / 0 °C 6.1: Et3N / CH2Cl2 / 4 h / 0 °C 7.1: NaN3 / dimethylformamide / 75 °C 8.1: hydrogen / Pd/C / ethyl acetate / 12 h / 760 Torr View Scheme

1.1: La(NO3)3·6H2O / acetonitrile / 1 h / 20 °C 2.1: potassium tert-butylate / N,N-dimethyl-formamide / 0.5 h / 0 °C 2.2: 42 h / 0 °C 3.1: trifluoroacetic acid / dichloromethane / 4 h / 20 °C 4.1: triethylamine / dichloromethane / 2.5 h / 20 °C 5.1: sodium azide / N,N-dimethyl-formamide / 3.5 h / 80 °C 6.1: palladium 10 on activated carbon; hydrogen / ethyl acetate / 12 h / 20 °C / 9000.9 Torr 7.1: (2R,3R)-(-)-di-O-(p-toluoyl)-tartaric acid / dimethyl sulfoxide / 3 h / 20 °C / Resolution of racemate 7.2: 1 h / 20 °C View Scheme

in N,N-dimethyl acetamide T=160°C; SolventTemperature;

1.1: NaI; Na2CO3 / dimethylformamide / 65 °C 2.1: aq. NaHCO3 / acetone 3.1: 95 percent / (COCl)2; DMSO; Et3N / CH2Cl2 / -78 - -60 °C 4.1: nitrosobenzene; D-proline / acetonitrile / 24 h / -20 °C 4.2: NaBH4 / methanol 4.3: 86 percent / CuSO4 / methanol 5.1: 96 percent / sodium hydride / tetrahydrofuran / 0 °C 6.1: Et3N / CH2Cl2 / 4 h / 0 °C 7.1: NaN3 / dimethylformamide / 75 °C 8.1: hydrogen / Pd/C / ethyl acetate / 12 h / 760 Torr 9.1: pyridine View Scheme

1.1: La(NO3)3·6H2O / acetonitrile / 1 h / 20 °C 2.1: potassium tert-butylate / N,N-dimethyl-formamide / 0.5 h / 0 °C 2.2: 42 h / 0 °C 3.1: trifluoroacetic acid / dichloromethane / 4 h / 20 °C 4.1: triethylamine / dichloromethane / 2.5 h / 20 °C 5.1: sodium azide / N,N-dimethyl-formamide / 3.5 h / 80 °C 6.1: palladium 10 on activated carbon; hydrogen / ethyl acetate / 12 h / 20 °C / 9000.9 Torr 7.1: pyridine / ethyl acetate / 1 h / 20 °C View Scheme

potassium carbonate in tetrahydrofuran T=20°C; 2 h; Inert atmosphere;