1: 93 percent / triethylamine / methanol / 48 h / Ambient temperature 2: 1.) triflic anhydride, diisopropylethylamine / 1.) CH2Cl2, -75 deg C, 20 min, 2.) CH2Cl2, -75 deg C -> room temp., 18 h 3: 95 percent / aq. HCl / methanol / 1.5 h / Heating 4: 15percent aq. NH3, Dowex View Scheme

1: 95 percent / aq. HCl / methanol / 1.5 h / Heating 2: 15percent aq. NH3, Dowex View Scheme

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

ammonium hydroxide; dowex Yield given;