sodium acetate in tetrahydrofuran; water T=20°C; 3 h;

sodium methylate in methanol 0.5 h; Ambient temperature;

sodium methylate in methanol; dichloromethane T=20°C; pH=9; 12 h;

1: 72 percent / BF3*OEt2 / CH2Cl2 / -20 - 0 °C / molecular sieves 4 Angstroem 2: 95 percent / NaOMe / methanol / 3 h / 0 deg C to room temperature View Scheme

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

1.1: NaN3; Bu4NCl / dimethylformamide / 24 h / 90 °C 1.2: 300 mg / Et3N; DMAP / CH2Cl2 2.1: 83 percent / Zn; NH4Cl / methanol 3.1: 76 percent / Hunig's base / CH2Cl2 4.1: 88 percent / HF*pyridine / acetonitrile / 10 h / 20 °C 5.1: 71 percent / BF3*Et2O / CH2Cl2 / 2 h 6.1: piperidine / dimethylformamide / 0.08 h 7.1: 7.1 mg / Et3N; DMAP / CH2Cl2 / 1 h / 20 °C 8.1: 72 percent / Grubbs second-generation ruthenium carbene catalyst / CH2Cl2 / 24 h / Heating 9.1: CF3CO2H / CH2Cl2; H2O / 12 h 10.1: 10.3 mg / NaOMe / methanol / 12 h View Scheme

1: 71 percent / BF3*Et2O / CH2Cl2 / 2 h 2: piperidine / dimethylformamide / 0.08 h 3: 7.1 mg / Et3N; DMAP / CH2Cl2 / 1 h / 20 °C 4: 72 percent / Grubbs second-generation ruthenium carbene catalyst / CH2Cl2 / 24 h / Heating 5: CF3CO2H / CH2Cl2; H2O / 12 h 6: 10.3 mg / NaOMe / methanol / 12 h View Scheme

1: piperidine / dimethylformamide / 0.08 h 2: 7.1 mg / Et3N; DMAP / CH2Cl2 / 1 h / 20 °C 3: 72 percent / Grubbs second-generation ruthenium carbene catalyst / CH2Cl2 / 24 h / Heating 4: CF3CO2H / CH2Cl2; H2O / 12 h 5: 10.3 mg / NaOMe / methanol / 12 h View Scheme

1: 71 percent / BF3*Et2O / CH2Cl2 / 2 h 2: piperidine / dimethylformamide / 0.08 h 3: 7.1 mg / Et3N; DMAP / CH2Cl2 / 1 h / 20 °C 4: 72 percent / Grubbs second-generation ruthenium carbene catalyst / CH2Cl2 / 24 h / Heating 5: CF3CO2H / CH2Cl2; H2O / 12 h 6: 10.3 mg / NaOMe / methanol / 12 h View Scheme

1: 76 percent / Hunig's base / CH2Cl2 2: 88 percent / HF*pyridine / acetonitrile / 10 h / 20 °C 3: 71 percent / BF3*Et2O / CH2Cl2 / 2 h 4: piperidine / dimethylformamide / 0.08 h 5: 7.1 mg / Et3N; DMAP / CH2Cl2 / 1 h / 20 °C 6: 72 percent / Grubbs second-generation ruthenium carbene catalyst / CH2Cl2 / 24 h / Heating 7: CF3CO2H / CH2Cl2; H2O / 12 h 8: 10.3 mg / NaOMe / methanol / 12 h View Scheme