1: LiBr; TMSCl / CH2Cl2 / 20 °C 2: NaH / dimethylformamide / 60 °C 3: n-BuLi / tetrahydrofuran / -78 °C 4: DIBALH / CH2Cl2 / -78 °C 5: imidazole / dimethylformamide 6: MgBr2 / diethyl ether / 20 °C 7: TiCl4; Zn; pyridine / 1,2-dimethoxy-ethane / Heating 8: PPTs / ethanol / 20 °C 9: Ti(i-PrO)4; L-(+)-DET; t-BuOOH / CH2Cl2 / -20 °C 10: I2; Ph3P; imidazole / diethyl ether; acetonitrile / 0 °C 11: NaBH3(CN) / tetrahydrofuran; hexamethylphosphoric acid triamide / 60 °C 12: TBAF / tetrahydrofuran View Scheme