potassium carbonate in dimethyl sulfoxide

1.1: thiourea / ethanol; water / 2 h / |Reflux; |Large scale 1.2: 3 h / |Reflux; |Large scale 2.1: chlorine / toluene / 0.42 h / 8 °C / |Cooling with ice 3.1: ammonia / 1 h / 5 - 15 °C 4.1: Na2WO4·2H2O; dihydrogen peroxide / water / 19 h / 15 - 35 °C 5.1: pyridinium tribromide; sulfuric acid / ethyl acetate / 1.5 h / 1 - 5 °C / |Large scale 6.1: bis[(1S,2R,3S,5S)-pinan-3-yl]chloroborane / tert-butyl methyl ether / 3.5 h / -40 - -32 °C / |Inert atmosphere 6.2: 2 h / 0 - 22 °C 7.1: potassium carbonate / dimethyl sulfoxide View Scheme

1.1: chlorine / toluene / 0.42 h / 8 °C / |Cooling with ice 2.1: ammonia / 1 h / 5 - 15 °C 3.1: Na2WO4·2H2O; dihydrogen peroxide / water / 19 h / 15 - 35 °C 4.1: pyridinium tribromide; sulfuric acid / ethyl acetate / 1.5 h / 1 - 5 °C / |Large scale 5.1: bis[(1S,2R,3S,5S)-pinan-3-yl]chloroborane / tert-butyl methyl ether / 3.5 h / -40 - -32 °C / |Inert atmosphere 5.2: 2 h / 0 - 22 °C 6.1: potassium carbonate / dimethyl sulfoxide View Scheme

1.1: triethylamine / tetrahydrofuran / 0 - 20 °C 2.1: water; tetrahydrofuran / 0 - 20 °C 2.2: pH 1 - 3 3.1: sodium hydrogencarbonate 3.2: 1 h / -40 °C View Scheme

1: With n-butyllithium in tetrahydrofuran; hexane T=-70 - -66°C; 3.5 h; Inert atmosphere; 2: With sulfur dioxide in tetrahydrofuran; hexane T=20°C; pH=4; 3: With NaOAc·3H2O; hydroxylamine-o-sulphonic acid in water T=0 - 25°C; 15 h;