1: 67 percent / 2-isobutyloxy-1-isobutyloxycarbonyl-1,2-dihydroquinoline / tetrahydrofuran / 1.) r.t., 2.) reflux 2: 76 percent / CF3COOH / CH2Cl2 / 1.5 h / Ambient temperature 3: 30 percent / H2 / 10percent Pd-C / methanol / 20 °C View Scheme

1: Ag2O / Heating 2: NaOH / methanol View Scheme

1: 1.) ammonium acetate, molecular sieves 3 Angstroem, 2.) methanolic HCl, NaBH3CN / 1.) methanol, 2 d, 2.) pH 3, r.t., 1 h 2: 84 percent / aq. NaHCO3 / toluene / 3 h / Ambient temperature 3: 82 percent / phosphate buffer, aq. NaOH / pig liver esterase / acetone / 7 h / 25 °C / pH 8 4: 83 percent / 4-dimethylaminopyridine, dicyclohexylcarbodiimide / CH2Cl2 / 1.) 0 deg C, 5 min, 2.) r.t., 3 h 5: 81 percent / aq. NaOH / methanol / 2.5 h / Ambient temperature View Scheme

1: 84 percent / aq. NaHCO3 / toluene / 3 h / Ambient temperature 2: 82 percent / phosphate buffer, aq. NaOH / pig liver esterase / acetone / 7 h / 25 °C / pH 8 3: 83 percent / 4-dimethylaminopyridine, dicyclohexylcarbodiimide / CH2Cl2 / 1.) 0 deg C, 5 min, 2.) r.t., 3 h 4: 81 percent / aq. NaOH / methanol / 2.5 h / Ambient temperature View Scheme

1: 82 percent / phosphate buffer, aq. NaOH / pig liver esterase / acetone / 7 h / 25 °C / pH 8 2: 83 percent / 4-dimethylaminopyridine, dicyclohexylcarbodiimide / CH2Cl2 / 1.) 0 deg C, 5 min, 2.) r.t., 3 h 3: 81 percent / aq. NaOH / methanol / 2.5 h / Ambient temperature View Scheme

1: 83 percent / 4-dimethylaminopyridine, dicyclohexylcarbodiimide / CH2Cl2 / 1.) 0 deg C, 5 min, 2.) r.t., 3 h 2: 81 percent / aq. NaOH / methanol / 2.5 h / Ambient temperature View Scheme