1: 1.) NaH / 1.) Et2O, 0 deg C to 10 deg C 2.) Et2O, 0 deg C to room temperature 2: 1.) HS(CH2)3SH, BF3*Et2O, 2.) CuO/CuCl2 / 1.) CH2Cl2, 0 deg C, 2.) H2O-acetone, reflux 3: 1.) (C6H11)2NMgBr / 1.) THF, -50 deg C, 2.) 0 deg C 4: 1.) NaOMe, 2.) Zn/AcOH, conc. HCl / 1.) CH2Cl2, MeOH, room temperature 2.) THF, room temperature 5: LiSPr / hexamethylphosphoric acid triamide / Ambient temperature View Scheme