1: p-toluenesulfonic acid monohydrate / benzene / 1 h / Ambient temperature 2: 1.41 g / 80percent acetic acid / 0.25 h / Ambient temperature 3: 76 percent / mercuric bromide, mercuric cyanide, molecular sieves 4A / acetonitrile / Ambient temperature 4: 82 percent / NaOMe / methanol / 1 h View Scheme

1: p-toluenesulfonic acid monohydrate / benzene / 1 h / Ambient temperature 2: 1.41 g / 80percent acetic acid / 0.25 h / Ambient temperature 3: 76 percent / mercuric bromide, mercuric cyanide, molecular sieves 4A / acetonitrile / Ambient temperature 4: 82 percent / NaOMe / methanol / 1 h View Scheme

With  water; trifluoroacetic acid 1 h;  Ambient temperature;   

Multi-step reaction with 3 steps 1: p-toluenesulfonic acid monohydrate / benzene / 1 h / Ambient temperature2: 1.41 g / 80percent acetic acid / 0.25 h / Ambient temperature3: 76 percent / mercuric bromide, mercuric cyanide, molecular sieves 4A / acetonitrile / Ambient temperature