1: 86 percent / dimethylsulfoxide / 1 h / 100 °C 2: 91 percent / toluene; methanol; hexane / 1 h / Ambient temperature 3: 82 percent / methanol / 2 h / Ambient temperature View Scheme

1: 86 percent / dimethylsulfoxide / 1 h / 100 °C 2: 91 percent / H2SO4 / CH2Cl2 / 12 h / Ambient temperature 3: 79 percent / LiOH*H2O / tetrahydrofuran; H2O / 3 h / Ambient temperature View Scheme