1.1: 63 percent / n-BuLi / tetrahydrofuran; hexane / 18 h / 20 °C 2.1: t-BuLi / tetrahydrofuran; pentane / 0.08 h / -78 °C 2.2: 60 percent / BF3*OEt2 / tetrahydrofuran; pentane / 3 h / -78 °C 3.1: 57 percent / second generation Grubbs catalyst / CH2Cl2 / 48 h / 50 - 55 °C 4.1: 89 percent / DMAP; 2,6-lutidine / pyridine / 1 h / 20 °C 5.1: 78 percent / pyridine; OsO4 / tetrahydrofuran / 5 h / 0 °C 6.1: 95 percent / pyridine / CH2Cl2 / 2 h / 0 °C 7.1: 84 percent / BnNMe3OH / tetrahydrofuran; methanol / 1 h / 0 °C 8.1: n-BuLi; WCl6 / hexane; tetrahydrofuran / 0.67 h / 0 - 20 °C 9.1: 95 percent / pyridinium p-toluenesulfonate / methanol / 6 h / 0 °C 10.1: 69 percent / pyridine; Dess-Martin periodinane / CH2Cl2 / 0.75 h / 20 °C 11.1: 40 percent / aq. HF / acetonitrile / 0.33 h / 20 °C View Scheme