N-bromosuccinmide; sulfuric acid in tetrahydrofuran T=-78°C; 1 h;

N-bromosuccinmide; sulfuric acid in tetrahydrofuran T=-78°C; 10 h;

1: 85 percent / dioxane / 10 h / 105 °C 2: 68 percent / NaH / tetrahydrofuran; dimethylformamide / 3 h / 25 °C 3: 91 percent / Bu3SnH, AIBN / benzene / 3 h / 80 °C 4: 1.) ozone, 2.) NaBH4 / 1.) EtOH, -78 deg C, 3 min, 2.) EtOH, H2O, -78 to 24 deg C, 4 h 5: 89 percent / Et3N / CH2Cl2 / 0.42 h / 0 °C 6: 75 percent / H2 / 10percent Pd/C / tetrahydrofuran / 7 h / 24 °C / 760 Torr 7: 100 percent / HCl / ethyl acetate / 0.17 h / 24 °C 8: 71 percent / 1-<3-(dimethylamino)propyl>-3-ethylcarbodiimide, K2CO3 / dimethylformamide / 20 h / 24 °C 9: 91 percent / NaH / tetrahydrofuran; dimethylformamide / 0.42 h / 24 °C View Scheme

1: 85 percent / dioxane / 10 h / 105 °C 2: 68 percent / NaH / tetrahydrofuran; dimethylformamide / 3 h / 25 °C 3: 91 percent / Bu3SnH, AIBN / benzene / 3 h / 80 °C 4: 1.) ozone, 2.) NaBH4 / 1.) EtOH, -78 deg C, 3 min, 2.) EtOH, H2O, -78 to 24 deg C, 4 h 5: 89 percent / Et3N / CH2Cl2 / 0.42 h / 0 °C 6: 75 percent / H2 / 10percent Pd/C / tetrahydrofuran / 7 h / 24 °C / 760 Torr 7: 100 percent / HCl / ethyl acetate / 0.17 h / 24 °C 8: 84 percent / 1-<3-(dimethylamino)propyl>-3-ethylcarbodiimide, Et3N / dimethylformamide / 45 h / 24 °C 9: 90 percent / NaH / tetrahydrofuran / 0.42 h / 24 °C View Scheme

in 1,4-dioxane T=105°C; 10 h;

1: 85 percent / dioxane / 10 h / 105 °C 2: 68 percent / NaH / tetrahydrofuran; dimethylformamide / 3 h / 25 °C 3: 91 percent / Bu3SnH, AIBN / benzene / 3 h / 80 °C 4: 1.) ozone, 2.) NaBH4 / 1.) EtOH, -78 deg C, 3 min, 2.) EtOH, H2O, -78 to 24 deg C, 4 h 5: 89 percent / Et3N / CH2Cl2 / 0.42 h / 0 °C 6: 75 percent / H2 / 10percent Pd/C / tetrahydrofuran / 7 h / 24 °C / 760 Torr 7: 100 percent / HCl / ethyl acetate / 0.17 h / 24 °C 8: 71 percent / 1-<3-(dimethylamino)propyl>-3-ethylcarbodiimide, K2CO3 / dimethylformamide / 20 h / 24 °C View Scheme