1: 93 percent / boron trichloride / CH2Cl2 / 3 h / Ambient temperature 2: 76 percent / KOH / dimethylsulfoxide; H2O / 5 h / 100 - 110 °C 3: 11 percent / N-chlorosuccinimide, toluene-4-sulfonic acid / dioxane / 20 h / Heating View Scheme

1: 93 percent / boron trichloride / CH2Cl2 / 3 h / Ambient temperature 2: 76 percent / KOH / dimethylsulfoxide; H2O / 5 h / 100 - 110 °C View Scheme

potassium hydroxide in water; dimethyl sulfoxide 0.75 h; Heating;