1: 35 percent / 5 N aq. acetic acid / 4 h / Heating 2: 50 percent / MnO2 / diethyl ether / 2 h / Heating 3: 83 percent / pyridine hydrochloride / 1.5 h / 185 °C 4: 77 percent / NaBH4 / methanol / 1 h / Ambient temperature View Scheme

hydrogen iodide 3 h; Heating;

1: 71 percent / 56percent HI / 3 h / Heating 2: 86 percent / pyridine / 1 h / Ambient temperature View Scheme