1: 93 percent / imidazole / dimethylformamide 2: 94 percent / xylene / 7 h / Heating 3: 81 percent / tetrahydrofuran / -78 °C 4: 85 percent / N-Methylmorpholine-N-oxide, OsO4 5: 93 percent / anhydr. CuSO4, TsOH 6: 75 percent / tetrahydrofuran / 24 h / Ambient temperature 7: 87 percent / Bu4NF / tetrahydrofuran / 4 h / Ambient temperature 8: 80 percent / PCC,molecular sieve / CH2Cl2 / 1 h / Ambient temperature 9: 1.) n-BuLi / 2.) THF, -40 to -30 deg C, 2 h and 0 deg C, 30 min. 10: 50percent aq. AcOH / 72 h / Ambient temperature View Scheme

sodium tetrahydroborate in ethanol

1: HBr, Ac2O 2: 1.) Hydrogen, Et3N 2.) MeONa / 2.) MeOH 3: 1.) HC(OEt)3 / 1.) AcOH / 1.) EtOAc 2.) 250 deg C 4: 82 percent / xylene / 18 h / Heating 5: 81 percent / I2 / tetrahydrofuran; H2O / 0 °C 6: 86 percent / NaBH4 / ethanol View Scheme

1: 1.) HC(OEt)3 / 1.) AcOH / 1.) EtOAc 2.) 250 deg C 2: 82 percent / xylene / 18 h / Heating 3: 81 percent / I2 / tetrahydrofuran; H2O / 0 °C 4: 86 percent / NaBH4 / ethanol View Scheme

1: 82 percent / xylene / 18 h / Heating 2: 81 percent / I2 / tetrahydrofuran; H2O / 0 °C 3: 86 percent / NaBH4 / ethanol View Scheme

1: 81 percent / I2 / tetrahydrofuran; H2O / 0 °C 2: 86 percent / NaBH4 / ethanol View Scheme

1H-imidazole in N,N-dimethyl-formamide

1: 93 percent / imidazole / dimethylformamide 2: 94 percent / xylene / 7 h / Heating 3: 81 percent / tetrahydrofuran / -78 °C 4: 85 percent / N-Methylmorpholine-N-oxide, OsO4 5: 93 percent / anhydr. CuSO4, TsOH 6: 75 percent / tetrahydrofuran / 24 h / Ambient temperature 7: 87 percent / Bu4NF / tetrahydrofuran / 4 h / Ambient temperature 8: 80 percent / PCC,molecular sieve / CH2Cl2 / 1 h / Ambient temperature 9: 1.) n-BuLi / 2.) THF, -40 to -30 deg C, 2 h and 0 deg C, 30 min. 10: 50percent aq. AcOH / 72 h / Ambient temperature View Scheme