1: 71 percent / Na-Hg / methanol 2: N,N-diisopropylethylamine / CH2Cl2 / 0.5 h / 0 °C 3: pyridinium p-toluenesulfonate / methanol / 1.) room temperature, overnight, 2.) 50 deg C, 1 h. 4: 1.) 2,4,6-trichlorobenzoyl chloride, Et3N, 2.) 4-dimethylaminopyridine / 1.) toluene, room temperature, 2 h, 2.) toluene, room temperature, 30 min. 5: 1.) pyridinium poly(hydrogen fluoride), 2.) Hg(ClO4)2*3H2O, CaCO3 / 1.) THF, room temperature, overnight, 2.) acetonitrile, H2O, room temperature, 5 min. View Scheme