1: 98 percent / imidazole / dimethylformamide / 10 h / Ambient temperature 2: 90 percent / iBu2AlH / hexane; toluene / 4 h / -78 °C 3: 12 percent / NaH / dimethylformamide / 1.5 h / Ambient temperature View Scheme

1: 98 percent / imidazole / dimethylformamide / 10 h / Ambient temperature 2: 90 percent / iBu2AlH / hexane; toluene / 4 h / -78 °C 3: 12 percent / NaH / dimethylformamide / 1.5 h / Ambient temperature 4: pyridinium p-toluenesulfonate / methanol / 30 h / Heating View Scheme