1.1: n-BuLi / tetrahydrofuran; hexane / 1.5 h / -20 °C 1.2: 61 percent / tetrahydrofuran; hexane / 2 h / Heating 2.1: 543 mg / Et2Zn / CH2Cl2 / 49 h / -20 - 25 °C 3.1: 310 mg / HCl / methanol / 16 h / 25 °C 4.1: 69 percent / pyridinium dichromate / dimethylformamide / 0 - 25 °C View Scheme

1.1: NaH / benzene / 20 °C 2.1: 90 percent / DIBAL-H / CH2Cl2; toluene / 1 h / -20 °C 3.1: SO3*pyridine / tetrahydrofuran / 20 °C 3.2: 67 percent / LiAlH4 / tetrahydrofuran / 20 °C 4.1: 92 percent / hydrochloric acid / tetrahydrofuran / Heating View Scheme

1.1: n-BuLi / tetrahydrofuran; hexane / 1.5 h / -20 °C 1.2: 61 percent / tetrahydrofuran; hexane / 2 h / Heating 2.1: 543 mg / Et2Zn / CH2Cl2 / 49 h / -20 - 25 °C 3.1: 310 mg / HCl / methanol / 16 h / 25 °C 4.1: 69 percent / pyridinium dichromate / dimethylformamide / 0 - 25 °C 5.1: diethyl ether View Scheme