1: MnO2 2: Et3N / N-(2-hydroxyethyl)-thiazolium bromide / dioxane / 20 h / 95 - 100 °C 3: sodium borohydride / tetrahydrofuran / 1 h / 0 °C 4: pyridine / 24 h / 25 °C 5: potassium t-butoxid, 18-Crown-6 / benzene / 0.5 h / Ambient temperature 6: sodium borohydride / propan-2-ol / 4 h / Heating 7: PBr3, LiBr, 2,4,6-collidine / 3 h / -40 - 0 °C 8: 1.) ZnBr, 2.) DBU / 1.) ether, -40 deg C to 0 deg C, 2 h, 2.) 50 deg C, 2 h View Scheme