1.1: imidazole / tetrahydrofuran / 0.5 h / 20 °C 2.1: 1.76 g / La(OTf)3 / toluene / 1 h / 20 °C 3.1: NaN3; Bu4NCl / dimethylformamide / 24 h / 90 °C 3.2: 300 mg / Et3N; DMAP / CH2Cl2 4.1: 83 percent / Zn; NH4Cl / methanol 5.1: 76 percent / Hunig's base / CH2Cl2 6.1: 88 percent / HF*pyridine / acetonitrile / 10 h / 20 °C 7.1: 71 percent / BF3*Et2O / CH2Cl2 / 2 h 8.1: piperidine / dimethylformamide / 0.08 h 9.1: 7.1 mg / Et3N; DMAP / CH2Cl2 / 1 h / 20 °C 10.1: 72 percent / Grubbs second-generation ruthenium carbene catalyst / CH2Cl2 / 24 h / Heating 11.1: CF3CO2H / CH2Cl2; H2O / 12 h 12.1: 10.3 mg / NaOMe / methanol / 12 h View Scheme