1: 80 percent / trifluoroacetic acid, water / 1 h / Ambient temperature 2: p-toluenesulfonic acid monohydrate / benzene / 1 h / Ambient temperature 3: 5.6 g / 80percent acetic acid / 0.25 h / Ambient temperature 4: 45 percent / mercuric bromide, mercuric cyanide, molecular sieves 4A / acetonitrile / Ambient temperature 5: 95 percent / NaOMe / methanol / 1 h View Scheme