1: 1.) polyphosphoric acid, 2.) potassium carbonate / 1.) dioxane, 60 deg C, 3 h, 2.) acetone, reflux, 50 h 2: 64 percent / potassium carbonate / acetone / 2 h / Heating 3: 93 percent / potassium carbonate / acetone / 4 h / Heating 4: 70 percent / NaBH4, PdCl2 / tetrahydrofuran; H2O / 1.5 h / 0 - 5 °C 5: 92 percent / toluene-p-sulfonic acid / toluene / 0.33 h / Heating 6: 95 percent / potassium carbonate / methanol / 1.5 h / Heating View Scheme

1: 64 percent / potassium carbonate / acetone / 2 h / Heating 2: 93 percent / potassium carbonate / acetone / 4 h / Heating 3: 70 percent / NaBH4, PdCl2 / tetrahydrofuran; H2O / 1.5 h / 0 - 5 °C 4: 92 percent / toluene-p-sulfonic acid / toluene / 0.33 h / Heating 5: 95 percent / potassium carbonate / methanol / 1.5 h / Heating View Scheme

1: 93 percent / potassium carbonate / acetone / 4 h / Heating 2: 70 percent / NaBH4, PdCl2 / tetrahydrofuran; H2O / 1.5 h / 0 - 5 °C 3: 92 percent / toluene-p-sulfonic acid / toluene / 0.33 h / Heating 4: 95 percent / potassium carbonate / methanol / 1.5 h / Heating View Scheme

1: 70 percent / NaBH4, PdCl2 / tetrahydrofuran; H2O / 1.5 h / 0 - 5 °C 2: 92 percent / toluene-p-sulfonic acid / toluene / 0.33 h / Heating 3: 95 percent / potassium carbonate / methanol / 1.5 h / Heating View Scheme

1: 92 percent / toluene-p-sulfonic acid / toluene / 0.33 h / Heating 2: 95 percent / potassium carbonate / methanol / 1.5 h / Heating View Scheme

1: 80 percent / sodium hydride / 0.5 h / 45 °C 2: 79 percent / pyridine / CHCl3 / 14 h / 60 °C View Scheme