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