1: 59 percent 2: 45 percent / H2O, NaOH / methanol / Ambient temperature 3: 2.) KOtBu / 1.) pyridine 2.) THF, room temperature 4: 36 percent / tetrahydrofuran 5: 94 percent / Na/BuOH / 80 °C 6: CrO3 7: Huang-Minlon reduction View Scheme