3-keto-2H,3H-1,2-benzisothiazole 1,1-dioxide in dichloromethane T=40°C; 24 h;

1: 99 percent / DIBALH / CH2Cl2; toluene / 1.17 h / -78 - 0 °C 2: 91 percent / saccharin / CH2Cl2 / 24 h / 40 °C View Scheme

1: 0.23 g / NBS; AIBN / benzene / 24 h / 80 °C 2: 5.52 g / AgOAc; H2O / ethanol; acetone / 24 h 3: 99 percent / DIBALH / CH2Cl2; toluene / 1.17 h / -78 - 0 °C 4: 91 percent / saccharin / CH2Cl2 / 24 h / 40 °C View Scheme

1: 5.52 g / AgOAc; H2O / ethanol; acetone / 24 h 2: 99 percent / DIBALH / CH2Cl2; toluene / 1.17 h / -78 - 0 °C 3: 91 percent / saccharin / CH2Cl2 / 24 h / 40 °C View Scheme

1: 90 percent / Mg / tetrahydrofuran / 17 h / 0 - 20 °C 2: 0.23 g / NBS; AIBN / benzene / 24 h / 80 °C 3: 5.52 g / AgOAc; H2O / ethanol; acetone / 24 h 4: 99 percent / DIBALH / CH2Cl2; toluene / 1.17 h / -78 - 0 °C 5: 91 percent / saccharin / CH2Cl2 / 24 h / 40 °C View Scheme