1.1: 49 percent / AgOCOCF3 / 1,2-dimethoxy-ethane / 15 h / 20 °C 2.1: 100 percent / aq. H2SO4 / 3 h / 20 °C 3.1: 87 percent / CAN / acetonitrile; H2O / 3 h / 20 °C 4.1: 14 percent / silica gel / CHCl3 / 0.02 h / 20 °C 5.1: UHP / trifluoroacetic acid / 4 h / 20 °C 5.2: 30 percent / TsCl / acetonitrile; H2O / 4 h / 60 °C View Scheme