1: 100 percent / tetrabutylammonium bromide; aq. NaOH / CH2Cl2 / 144 h 2: 3-chloroperbenzoic acid / ethyl acetate / 72 h / 20 °C 3: aq. NaOH / methanol / 2 h / 20 °C View Scheme

1: 100 percent / tetrabutylammonium bromide; aq. NaOH / CH2Cl2 / 144 h 2: 3-chloroperbenzoic acid / ethyl acetate / 72 h / 20 °C 3: aq. NaOH / methanol / 2 h / 20 °C 4: 75 percent / KOH / dimethylsulfoxide / 24 h View Scheme

1: 100 percent / tetrabutylammonium bromide; aq. NaOH / CH2Cl2 / 144 h 2: 3-chloroperbenzoic acid / ethyl acetate / 72 h / 20 °C 3: aq. NaOH / methanol / 2 h / 20 °C 4: 75 percent / KOH / dimethylsulfoxide / 24 h 5: 85 percent / NaN3 / dimethylformamide; H2O / 4 h / 90 °C View Scheme

sodium hydroxide; tetrabutylammomium bromide in dichloromethane T=20°C; 24 h;

1: 73 percent / 60percent aq. KOH / ethanol / 3 h / 50 - 60 °C 2: 65 percent / Br2 / CCl4 / 0.5 h / Ambient temperature 3: 86 percent / 20percent aq. KOH / acetone / Ambient temperature View Scheme