hydrogenchloride; 4 A molecular sieve in diethyl ether 3 h;

hydrogenchloride in diethyl ether T=5°C; 17 h;

hydrogenchloride in diethyl ether T=5°C;

hydrogenchloride in diethyl ether

toluene-4-sulfonic acid in dichloromethane 2 h; Ambient temperature;

toluene-4-sulfonic acid in dichloromethane 2 h; Ambient temperature;

1: (iBu)2AlH 2: acid View Scheme

1: 1) NaBH4, 2) pyridine / 1) EtOH, 4 h, r.t., 2) CH2Cl2, 5 h, r.t. 2: 56 percent / dimethylsulfoxide / 2.5 h / 100 °C 3: 99 percent / HCl / diethyl ether / 17 h / -5 °C 4: 80 percent / 0.2 N HCl / diethyl ether / 17 h / Ambient temperature 5: 98 percent / 20percent diisobutyl aluminium hydride / toluene; hexane / 2 h / -40 °C 6: 99 percent / p-toluenesulfonic acid, molecular sieve 4 Angstroem / diethyl ether; petroleum ether / 1 h / Ambient temperature 7: 80 percent / HCl / diethyl ether View Scheme

1: 56 percent / dimethylsulfoxide / 2.5 h / 100 °C 2: 99 percent / HCl / diethyl ether / 17 h / -5 °C 3: 80 percent / 0.2 N HCl / diethyl ether / 17 h / Ambient temperature 4: 98 percent / 20percent diisobutyl aluminium hydride / toluene; hexane / 2 h / -40 °C 5: 99 percent / p-toluenesulfonic acid, molecular sieve 4 Angstroem / diethyl ether; petroleum ether / 1 h / Ambient temperature 6: 80 percent / HCl / diethyl ether View Scheme

1: 1) NaBH4, BF3*Et2O, 2) pyridine / 1) THF, 17 h, 25 deg C, 2) CH2Cl2, 5 h, r.t. 2: 56 percent / dimethylsulfoxide / 2.5 h / 100 °C 3: 99 percent / HCl / diethyl ether / 17 h / -5 °C 4: 80 percent / 0.2 N HCl / diethyl ether / 17 h / Ambient temperature 5: 98 percent / 20percent diisobutyl aluminium hydride / toluene; hexane / 2 h / -40 °C 6: 99 percent / p-toluenesulfonic acid, molecular sieve 4 Angstroem / diethyl ether; petroleum ether / 1 h / Ambient temperature 7: 80 percent / HCl / diethyl ether View Scheme