1: 68 percent / DBN / toluene / 10 h / Heating 2: 86 percent / OsO4; pyridine / diethyl ether; tetrahydrofuran / 18 h / 20 °C 3: 86 percent / DBU / toluene / 4 h / Heating 4: pyridinium p-toluenesulfonic acid / methanol / 0.5 h / 20 °C 5: 15 mg / DMAP; imidazole / dimethylformamide / 5 h / 20 °C 6: 97 percent / H2 / Pd(OH)2 / ethanol / 1 h / 20 °C 7: 94 percent / pyridine / CH2Cl2 / 1 h / -78 - 0 °C 8: 66 percent / DMAP / CH2Cl2 / 6 h / 20 °C 9: 83 percent / tetrahydrofuran / 0.33 h / -78 °C 10: 88 percent / HF*pyridine / tetrahydrofuran / 2 h / 20 °C 11: 94 percent / pyridine / CH2Cl2 / 3 h / 20 °C 12: 80 percent / TASF / tetrahydrofuran / 48 h / 20 °C 13: 77 percent / LHMDS / tetrahydrofuran / -78 - 0 °C 14: 84 percent / Zn; aq. AcOH / 16 h / 20 °C View Scheme

1: 68 percent / DBN / toluene / 10 h / Heating 2: 86 percent / OsO4; pyridine / diethyl ether; tetrahydrofuran / 18 h / 20 °C 3: 86 percent / DBU / toluene / 4 h / Heating 4: pyridinium p-toluenesulfonic acid / methanol / 0.5 h / 20 °C 5: 15 mg / DMAP; imidazole / dimethylformamide / 5 h / 20 °C 6: 97 percent / H2 / Pd(OH)2 / ethanol / 1 h / 20 °C 7: 94 percent / pyridine / CH2Cl2 / 1 h / -78 - 0 °C 8: 66 percent / DMAP / CH2Cl2 / 6 h / 20 °C 9: 83 percent / tetrahydrofuran / 0.33 h / -78 °C 10: 88 percent / HF*pyridine / tetrahydrofuran / 2 h / 20 °C 11: 94 percent / pyridine / CH2Cl2 / 3 h / 20 °C 12: 80 percent / TASF / tetrahydrofuran / 48 h / 20 °C View Scheme