1: 85 percent / 85percent H3PO4 / 3 h / Ambient temperature 2: 92 percent / pyridine / Ambient temperature 3: 1.) BuLi, diisopropylamine / 1.) THF, hexane, -78 deg C, 1 h, 2.) -78 deg C, 2 h 4: 83 percent / trifluoroacetic acid (TFA) / Ambient temperature 5: 92 percent / Li, NH3 / tetrahydrofuran 6: 87 percent / KOH / H2O / 24 h / Heating View Scheme

1: 85percent H3PO4 2: pyridine View Scheme

Multi-step reaction with 5 steps 1: phosphoric acid / 5 h / 20 °C / Inert atmosphere2: pyridine / Inert atmosphere3: N-bromosuccinmide / acetic acid / 24 h / 20 °C / Inert atmosphere4: sulfuric acid / methanol / 5 h / 20 °C / Inert atmosphere5: chloro-trimethyl-silane; sodium iodide / acetonitrile / 2 h / Reflux