1.1: n-butyllitium / tetrahydrofuran; hexane; hexamethylphosphoric acid triamide / 1 h / -78 °C 1.2: 73 percent / tetrahydrofuran; hexane; hexamethylphosphoric acid triamide / 4 h / -78 °C 2.1: (EtO)3SiH / Cp*Ru(CH3CN)3PF6 / CH2Cl2 / 3 h / 20 °C 2.2: 92 percent / cesium fluoride; ethanol / CH2Cl2 / 12 h / 20 °C 3.1: pyridine / CH2Cl2 4.1: DIBAL-H / tetrahydrofuran / -78 °C 5.1: potassium hexamethyldisilylazide / 1,2-dimethoxy-ethane / 1 h / -78 °C 5.2: 1,2-dimethoxy-ethane / -78 - 20 °C 6.1: CAN; H2O / acetone 7.1: aq. NaOH / tetrahydrofuran; methanol 8.1: 61 percent / MsCl; Et3N; 2,4,6-trichlorobenzoyl chloride / 4-DMAP / toluene / Heating 9.1: 77 percent / TBAF / tetrahydrofuran / 20 °C View Scheme