1: 1.) sodium hydride / 1,2-dimethoxy-ethane / 1.) 0.5 h, 70 deg, 2.) 1 h, reflux 2: 79.5 percent / sodium borohydride / methanol / 1 h / Ambient temperature 3: 44.3 percent / pyridine / 8 h / Ambient temperature 4: 33.6 percent / lithium bromide / dimethylformamide / 5 h / 80 °C 5: 78.7 percent / methyl iodide / H2O; acetone / 5 h / Heating View Scheme