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

1: 82 percent / RuCl2[(1,3-dimesitylimidazolidine-2-yl)(PCy3)(benzylidene)] / CH2Cl2 / 36 h / Heating 2: piperidine / dimethylformamide / 0.08 h 3: 12 mg / DMAP; Et3N / CH2Cl2 / 3 h / 20 °C 4: 72 percent / TFA / CH2Cl2; H2O / 2 h 5: 40 percent / TBAF / tetrahydrofuran / 1 h / 20 °C View Scheme