hydrogenchloride in methanol T=20°C; 3 h;

sodium ethanolate in ethanol 0.05 h; Heating;

1: 1.) NaOEt / 1.) EtOH, RT, 20 min, 2.) EtOH, reflux, 6 h 2: 98 percent / KOH / ethanol / 4 h / Heating 3: 91 percent / aq. CF3COOH / CH2Cl2 / 12 h / Heating 4: 99 percent / pyridine / CH2Cl2 / 1.5 h / Ambient temperature 5: 33 percent / H2 / 5percent Pd/C / ethyl acetate / 6 h / Ambient temperature 6: 99 percent / NaOEt / ethanol / 0.05 h / Heating View Scheme

1: 99 percent / pyridine / CH2Cl2 / 1.5 h / Ambient temperature 2: 33 percent / H2 / 5percent Pd/C / ethyl acetate / 6 h / Ambient temperature 3: 99 percent / NaOEt / ethanol / 0.05 h / Heating View Scheme

1: 91 percent / aq. CF3COOH / CH2Cl2 / 12 h / Heating 2: 99 percent / pyridine / CH2Cl2 / 1.5 h / Ambient temperature 3: 33 percent / H2 / 5percent Pd/C / ethyl acetate / 6 h / Ambient temperature 4: 99 percent / NaOEt / ethanol / 0.05 h / Heating View Scheme

1: 1.) NaOEt / 1.) EtOH, RT, 20 min, 2.) EtOH, reflux, 6 h 2: 98 percent / KOH / ethanol / 4 h / Heating 3: 91 percent / aq. CF3COOH / CH2Cl2 / 12 h / Heating 4: 99 percent / pyridine / CH2Cl2 / 1.5 h / Ambient temperature 5: 33 percent / H2 / 5percent Pd/C / ethyl acetate / 6 h / Ambient temperature 6: 99 percent / NaOEt / ethanol / 0.05 h / Heating View Scheme

1: 98 percent / imidazole / dimethylformamide / 16 h / Ambient temperature 2: 1.) butyllithium / 1.) THF, hexane, 15 min, 2.) THF, hexane, room temperature, 1 h 3: AD-mix-α / 2-methyl-propan-2-ol; H2O / 18 h 4: pyridine / 2 h 5: sodium hydroxide, tetrabutylammonium hydrogen sulfate / CH2Cl2; H2O / 2 h 6: 1.) butyllithium / 1.) THF, hexane, 1 h, 2.) THF, hexane, 12 h 8: 95 percent / tetrabutylammonium fluoride / tetrahydrofuran / 1 h View Scheme

1: AD-mix-α / 2-methyl-propan-2-ol; H2O / 18 h 2: pyridine / 2 h 3: sodium hydroxide, tetrabutylammonium hydrogen sulfate / CH2Cl2; H2O / 2 h 4: 1.) butyllithium / 1.) THF, hexane, 1 h, 2.) THF, hexane, 12 h 6: 95 percent / tetrabutylammonium fluoride / tetrahydrofuran / 1 h View Scheme

1: 1.) butyllithium / 1.) THF, hexane, 15 min, 2.) THF, hexane, room temperature, 1 h 2: AD-mix-α / 2-methyl-propan-2-ol; H2O / 18 h 3: pyridine / 2 h 4: sodium hydroxide, tetrabutylammonium hydrogen sulfate / CH2Cl2; H2O / 2 h 5: 1.) butyllithium / 1.) THF, hexane, 1 h, 2.) THF, hexane, 12 h 7: 95 percent / tetrabutylammonium fluoride / tetrahydrofuran / 1 h View Scheme

1: 1.) butyllithium / 1.) THF, hexane, 1 h, 2.) THF, hexane, 12 h 3: 95 percent / tetrabutylammonium fluoride / tetrahydrofuran / 1 h View Scheme