1: 77 percent / 1) LDA / tetrahydrofuran / -78 °C / 1) 40 min, 2) 1 h 2: 91 percent / LiBH4, methanol / 1,2-dimethoxy-ethane / 2 h / 50 °C 3: imidazole / dimethylformamide / 40 °C 4: 93 percent / imidazole / dimethylformamide / 40 °C 5: 91 percent / 1N HCl / methanol / 0 °C 6: hexamethyldisilazane / pyridine 7: trimethylsilyl triflate, Et3N / CH2Cl2 / 24 h / 40 °C 8: 1N HCl / methanol / 0.17 h / 0 °C 9: 92 percent / pyridinium dichromate / dimethylformamide / Ambient temperature View Scheme