hydrogen; palladium on activated charcoal in ethanol 1 h;

potassium carbonate in acetone T=20°C; 5 h;

1.1: 70 percent / acetic acid; tetrabutylammonium fluoride / tetrahydrofuran / 0.67 h / 0 °C 2.1: potassium carbonate / acetone / 0.25 h / 20 °C 2.2: 81 percent / acetone / 17 h / Heating 3.1: 82 percent / H2 / Pd/C / ethanol / 1 h View Scheme

1.1: 85 percent / imidazole / CH2Cl2 / 20 °C 2.1: 100 percent / tetrabutylammonium bromide; sodium hydroxide / CH2Cl2 / 18 h / 20 °C 3.1: 70 percent / acetic acid; tetrabutylammonium fluoride / tetrahydrofuran / 0.67 h / 0 °C 4.1: potassium carbonate / acetone / 0.25 h / 20 °C 4.2: 81 percent / acetone / 17 h / Heating 5.1: 82 percent / H2 / Pd/C / ethanol / 1 h View Scheme

1.1: potassium carbonate / acetone / 0.25 h / 20 °C 1.2: 81 percent / acetone / 17 h / Heating 2.1: 82 percent / H2 / Pd/C / ethanol / 1 h View Scheme

1.1: potassium carbonate / acetone / 0.25 h / 20 °C 1.2: 81 percent / acetone / 17 h / Heating 2.1: 82 percent / H2 / Pd/C / ethanol / 1 h View Scheme