1.1: LDA / tetrahydrofuran / 1 h / -78 °C 1.2: 71 percent / tetrahydrofuran / 1 h / -78 °C 2.1: 90 percent / Ac2O; pyridine; DMAP / 48 h / 50 °C 3.1: 88 percent / aq. TsOH / tetrahydrofuran / 12 h / 50 °C 4.1: 73 percent / TEMPO; KBr; aq. NaOCl / NaHCO3 / CH2Cl2 / 0.5 h / -10 °C View Scheme

1: 83 percent / SnCl2 / CH2Cl2 / 25 °C 2: 90 percent / H2 / (S)-BINAP-Ru(II) / methanol / 6 h / 100 °C / 20685.9 Torr 3: NaBH4; CuSO4 / ethanol / 7 h 4: Et3N / CH2Cl2 / 6 h / 0 °C 5: pTSA / methanol / 10 h 6: PCC / CH2Cl2 / 3 h 7: Ag2O; NaOH / ethanol 8: KOH; Na2S*9H2O; HCl / H2O; dimethylformamide / 28 h / 80 °C View Scheme

1: 83 percent / SnCl2 / CH2Cl2 / 25 °C 2: 90 percent / H2 / (S)-BINAP-Ru(II) / methanol / 6 h / 100 °C / 20685.9 Torr 3: NaBH4; CuSO4 / ethanol / 7 h 4: Et3N / CH2Cl2 / 6 h / 0 °C 5: pTSA / methanol / 10 h 6: PCC / CH2Cl2 / 3 h 7: Ag2O; NaOH / ethanol 8: 45 percent / KOH; Na2S*9H2O; HCl / H2O; dimethylformamide / 28 h / 80 °C View Scheme

1.1: potassium tert-butylate / tetrahydrofuran / 0.5 h / 20 °C 1.2: 0 - 20 °C 2.1: hydrogenchloride; water / diethyl ether / 4 h / 20 °C View Scheme

boron trifluoride diethyl etherate in dichloromethane T=0°C; 3 h;

dibutyltin triflate in toluene T=-40°C; 3 h;

1: 91 percent / CH2Cl2 / 16 h 2: 99 percent / DIBAL-H / toluene / 0.5 h / -78 °C 3: 76 percent / MnO2 / CH2Cl2 / 24 h 4: 97 percent / n-BuLi / tetrahydrofuran; hexane / 1.) -78 deg C, 10 min; 2.) from -78 deg C to r.t. 5: 84 percent / CSA / methanol / 16 h / Ambient temperature View Scheme

1.1: n-BuLi; HMPA / tetrahydrofuran; hexane / 1 h / 0 °C 1.2: tetrahydrofuran; hexane / 0 °C 2.1: PTSA / methanol / 1 h / 20 °C 3.1: Jones reagent / acetone / 0 - 20 °C 4.1: 60 percent / Li; liq. NH3 / tetrahydrofuran / 2 h / cooling View Scheme

1: 1) t-BuOK / 1) THF, 0 deg C, 30 min, 2) THF, 0 deg C, 4 h 2: H2, NaHCO3 / 10percent Pd/C / methanol / 760 Torr 3: 14.2 g / KOH / ethanol / Heating 4: 83 percent Turnov. / pyridine / CH2Cl2 / 1.) 0 deg C, 2 h, 2.) r.t., 3 h 5: DOWEX-50X8-400R, MeOH / 20 h / 50 °C 6: Et3N / CH2Cl2 / 1 h / 0 °C 7: 10.6 g / LiI / dimethylformamide / 3.5 h / 90 °C 8: 72 percent Turnov. / AgNO2 / diethyl ether / 1.) 0 deg C, 1 d, 2.) r.t., 12 d, in darkness View Scheme

2: p-TsOH / methanol 3: H2 / Pd/C 4: CrO3, pyridine, HCl View Scheme