1: Et3N / tetrahydrofuran / 0.17 h / 20 °C 2: KOt-Bu / tetrahydrofuran / 0.5 h / 0 °C 3: 0.327 g / TBAF / tetrahydrofuran / 12 h 4: Et3N / CH2Cl2 / 0.17 h / 20 °C 5: 0.127 g / NaH / dimethylformamide / 0.25 h / Heating 6: TFA / CH2Cl2 / 1.5 h View Scheme

1: Et3N / tetrahydrofuran / 0.17 h / 20 °C 2: KOt-Bu / tetrahydrofuran / 0.5 h / 0 °C 3: 0.327 g / TBAF / tetrahydrofuran / 12 h View Scheme

Multi-step reaction with 7 steps 1.1: 94 percent / PBr3 / diethyl ether / 1.5 h2.1: 75 percent / NaH / tetrahydrofuran / 0 - 20 °C3.1: n-BuLi; (-)-sparteine / toluene; hexane / 1 h / -78 °C3.2: 83 percent / toluene; hexane / 1.17 h / -78 °C4.1: aq. HCl / CHCl3 / 3 h5.1: 0.761 g / NaBH4 / methanol / 1 h6.1: ammonium formate / Pd/C / methanol / 0.5 h / Heating7.1: 0.702 g / CH2Cl2 / 2 h / 20 °C  

Multi-step reaction with 2 steps 1: ammonium formate / Pd/C / methanol / 0.5 h / Heating2: 0.702 g / CH2Cl2 / 2 h / 20 °C