1: imidazol-DMAP / dimethylformamide 2: lithium diisopropylamide / tetrahydrofuran 3: 76 percent / t-BuOK / tetrahydrofuran 4: 1) NaBH4; 2) aq. HCl / 1) MeOH 5: 1) lithium diisopropylamide; 2) MsCl/Huenig base, pyridine; 3) DBU / 1) THF; 2) CH2Cl2; 3) benzene 6: 78 percent / HF / H2O; acetonitrile View Scheme