trifluoroacetic anhydride in toluene T=25°C; 1 h;

1: 45 g / 12 N HCl / H2O / 3 h / Heating 2: trifluoroacetic anhydride / toluene / 1 h / 25 °C View Scheme

lithium aluminium tetrahydride in tetrahydrofuran; toluene T=0 - 5°C;

1: LiAlH4 / tetrahydrofuran; toluene / 0 - 5 °C 2: 24 g / sodium tungstate dihydrate, 30 percent hydrogen peroxide / H2O; ethyl acetate; toluene / 1) 0 - 15 deg C, 30 min, 2) 25 deg C, 2 h 3: 95 percent / pyridine / tetrahydrofuran / 48 h / 25 - 30 °C 4: 89.6 percent / H2SO4 / 20 - 25 °C 5: chlorosulfonic acid / 12 h / 50 °C 6: conc. NH4OH / tetrahydrofuran / 1 h / 0 - 5 °C 7: 1) borane-dimethyl sulfide, 2) H2SO4 / 1) THF, r.t. View Scheme

1.1: thionyl chloride; sulfuryl dichloride / 10 h / 28 °C / |Inert atmosphere 2.1: ammonia / methanol; acetone / -10 °C / |Inert atmosphere 3.1: Na2WO4·2H2O / methanol; water / 47 h / 10 - 50 °C / |Inert atmosphere 4.1: sodium tetrahydroborate / water; tetrahydrofuran / 2 h / 15 °C / |Inert atmosphere 4.2: 2 h / 40 °C 5.1: methanesulfonic acid / water; acetonitrile / 19 h / 10 - 87 °C / |Inert atmosphere; |Reflux 5.2: 4 h / 7 - 40 °C / pH 7.3 View Scheme