sodium hydride in dimethyl sulfoxide 1) room temp., 30 min; 2) 90 deg C, 1 h;

1: 1) sodium hydride; 2) 3N HCl / 1) DMF, 10 min; 2) room temp., 3 h 2: 97 percent / 0.94 N borane / tetrahydrofuran / 1 h / Heating 3: 15 percent / sodium hydride / dimethylsulfoxide / 1) room temp., 30 min; 2) 90 deg C, 1 h View Scheme

1: 83 percent / chlorosulfonic acid / 1 h / Ambient temperature 2: 88 percent / conc. sulfuric acid, zinc dust / H2O / 16 h / Heating 3: 1) sodium hydride; 2) 3N HCl / 1) DMF, 10 min; 2) room temp., 3 h 4: 97 percent / 0.94 N borane / tetrahydrofuran / 1 h / Heating 5: 15 percent / sodium hydride / dimethylsulfoxide / 1) room temp., 30 min; 2) 90 deg C, 1 h View Scheme

1: 88 percent / conc. sulfuric acid, zinc dust / H2O / 16 h / Heating 2: 1) sodium hydride; 2) 3N HCl / 1) DMF, 10 min; 2) room temp., 3 h 3: 97 percent / 0.94 N borane / tetrahydrofuran / 1 h / Heating 4: 15 percent / sodium hydride / dimethylsulfoxide / 1) room temp., 30 min; 2) 90 deg C, 1 h View Scheme

1: 1) sodium hydride; 2) 3N HCl / 1) DMF, 10 min; 2) room temp., 3 h 2: 97 percent / 0.94 N borane / tetrahydrofuran / 1 h / Heating 3: 15 percent / sodium hydride / dimethylsulfoxide / 1) room temp., 30 min; 2) 90 deg C, 1 h View Scheme

1: 97 percent / 0.94 N borane / tetrahydrofuran / 1 h / Heating 2: 15 percent / sodium hydride / dimethylsulfoxide / 1) room temp., 30 min; 2) 90 deg C, 1 h View Scheme