1: 1.) 1-chloroethyl chloroformate, 3.) Et3N / 1.) toluene, reflux, 16 h, 2.) MeOH, reflux, 16 h, 3.) room temperature, 14 h 2: 78 percent / Na2CO3*H2O / tetrahydrofuran; H2O / 16 h 3: 96 percent / aq. NaOH / ethanol / 1.) 0 deg C, 1 h, 2.) room temperature, 1.5 h 4: 80 percent / 0.67 h / 105 - 110 °C 5: 94 percent / Na2CO3, aq. H2O2 / H2O / 24 h / Ambient temperature 6: 96 percent / DMAP / CH2Cl2 / 12 h / Ambient temperature 7: 90 percent / TFA / CH2Cl2 / 1 h / Ambient temperature 8: 75 percent / NaBH3CN / acetonitrile / 1 h / Ambient temperature 9: 93 percent / NaNO2 / acetic acid; acetic anhydride / 1.) 0 deg C, 16 h, 2.) room temperature, 8 h 10: 95 percent / CH2Cl2 View Scheme

1: 1.) 1-chloroethyl chloroformate, 3.) Et3N / 1.) toluene, reflux, 16 h, 2.) MeOH, reflux, 16 h, 3.) room temperature, 14 h 2: 78 percent / Na2CO3*H2O / tetrahydrofuran; H2O / 16 h 3: 96 percent / aq. NaOH / ethanol / 1.) 0 deg C, 1 h, 2.) room temperature, 1.5 h 4: 80 percent / 0.67 h / 105 - 110 °C 5: 94 percent / Na2CO3, aq. H2O2 / H2O / 24 h / Ambient temperature 6: 96 percent / DMAP / CH2Cl2 / 12 h / Ambient temperature 7: 90 percent / TFA / CH2Cl2 / 1 h / Ambient temperature 8: 75 percent / NaBH3CN / acetonitrile / 1 h / Ambient temperature 9: 93 percent / NaNO2 / acetic acid; acetic anhydride / 1.) 0 deg C, 16 h, 2.) room temperature, 8 h View Scheme