1: 69 percent / SO2Cl2 / CH2Cl2 2: 71 percent / p-toluenesulfonic acid / benzene / 3 h / Heating 3: 72 percent / tetrabutylammonium bromide / benzene / 3 h / Heating 4: immobilized baker's yeast, glucose / H2O / 72 h / 35 °C 5: 56 percent / Ba(OH)2 / H2O; ethanol / 3 h / 85 °C View Scheme

pyridine in dichloromethane; water; tert-butyl alcohol

1: 63.4 percent / lithium diisopropylamide 2: ethyl acetate 3: 10 percent potassium carbonate / benzene View Scheme

1: 63.4 percent / lithium diisopropylamide 2: ethyl acetate 3: 10 percent potassium carbonate / benzene View Scheme

1: ethyl acetate 2: 10 percent potassium carbonate / benzene View Scheme

in benzene

1: 69 percent / SO2Cl2 / CH2Cl2 2: 71 percent / p-toluenesulfonic acid / benzene / 3 h / Heating 3: 72 percent / tetrabutylammonium bromide / benzene / 3 h / Heating 4: immobilized baker's yeast, glucose / H2O / 72 h / 35 °C 5: 56 percent / Ba(OH)2 / H2O; ethanol / 3 h / 85 °C View Scheme

1: 69 percent / SO2Cl2 / CH2Cl2 2: 71 percent / p-toluenesulfonic acid / benzene / 3 h / Heating View Scheme