1: 1.) CH3CHO, SmI2, 2.) NaOMe / 1.) THF, -10 deg C, 2 h, 2.) CH2Cl2, CH3OH, 12 h 2: 75 percent / pyridine / -30 °C 3: 80 percent / BF3*Et2O / methanol / Ambient temperature 4: 97 percent / pyridine / 12 h / Ambient temperature 5: 87 percent / NaN3 / dimethylformamide / 48 h / 90 - 100 °C 6: 100 percent / NaOMe / methanol / 2 h 7: 87 percent / H2O, pyrydyne, H2S / Ambient temperature View Scheme

1: 1.) CH3CHO, SmI2, 2.) NaOMe / 1.) THF, -10 deg C, 2 h, 2.) CH2Cl2, CH3OH, 12 h 2: 75 percent / pyridine / -30 °C 3: 80 percent / BF3*Et2O / methanol / Ambient temperature View Scheme