ethylenediaminetetraacetic acid; D,L-Cysteine; papain in dichloromethane T=37°C; 8 h;

1-n-butyl-3-methylimidazolium bistrifluoromethylsulfonylamide T=30 - 35°C; 0.166667 h; neat (no solvent); chemoselective reaction;

sodium hydrogencarbonate in CH2Cl2/H2O

in benzene 30 h; Ambient temperature;

1: 92 percent / K2CO3 / acetone / 24 h / Ambient temperature 2: 99 percent / NaOH / ethanol / Ambient temperature 3: 73.9 percent / 1-<3-(dimethylamino)propyl>-3-ethylcarbodiimide hydrochloride, 1-hydroxybenzotriazole, Et3N / dimethylformamide / 20 h / Ambient temperature 4: 91 percent / HCl / dioxane / 2 h / Ambient temperature 5: 72 percent / 1-<3-(dimethylamino)propyl>-3-ethylcarbodiimide hydrochloride, 1-hydroxybenzotriazole, Et3N / dimethylformamide / 24 h / Ambient temperature 6: 96 percent / HCl / dioxane / 2 h / Ambient temperature 7: 13.5 percent / Et3N / CH2Cl2 / 1.) -60 deg C, 30 min, 2.) 10 deg C, 1 h 8: 14 percent / m-CPBA / CH2Cl2 / 48 h / Ambient temperature View Scheme

1: 92 percent / K2CO3 / acetone / 24 h / Ambient temperature 2: 99 percent / NaOH / ethanol / Ambient temperature View Scheme

diisobutylaluminium hydride in tetrahydrofuran

1: 18-crown-6 ether; potassium carbonate / N,N-dimethyl-formamide / 24 h / 40 °C 2: lithium aluminium tetrahydride / tetrahydrofuran / 0 - 20 °C View Scheme

1: 18-crown-6 ether; potassium carbonate / N,N-dimethyl-formamide / 24 h / 40 °C 2: lithium aluminium tetrahydride / tetrahydrofuran / 0 - 20 °C 3: acetyl chloride / methanol; ethyl acetate / 24.5 h / 0 - 20 °C View Scheme