1: 1.) triflic anhydride, diisopropylethylamine / 1.) CH2Cl2, -75 deg C, 20 min, 2.) CH2Cl2, -75 deg C -> room temp., 18 h 2: 95 percent / aq. HCl / methanol / 1.5 h / Heating View Scheme

potassium carbonate in methanol 16 h; Heating;

1: 1.) triflic anhydride, diisopropylethylamine / 1.) CH2Cl2, -75 deg C, 20 min, 2.) CH2Cl2, -75 deg C -> room temp., 18 h 2: 95 percent / aq. HCl / methanol / 1.5 h / Heating 3: 15percent aq. NH3, Dowex View Scheme

1: 69 percent / CH2Cl2 2: 87 percent / aq. NaOH / methanol / 0.25 h View Scheme

1: 1.) ClC(S)OPh, NaHCO3, 2.) Et3N / 1.) THF, H2O, room temperature, 15 h, 2.) MeOH, room temperature, 22 h 2: 1.) LiOH*H2O, 2.) HCl / 1.) THF, H2O, room temperature, 18 h, 5.) CH2Cl2, room temperature, 15 min View Scheme