1: 87 percent / dioxane 2: sodium metaperiodate 3: 5percent H2SO4-AcOH / tetrahydrofuran / 3 h / Heating 5: 1.) H2, 5percent HCl, 2.) O3 / 1.) r.t., 4 d 6: 1.) O3, 2.) Me2S 7: sulphamic acid, sodium chlorite 8: H2SO4 / acetone 9: 52 percent / AlCl3, Me2S / CH2Cl2 / -10 °C 10: 68 percent / 5percent HCl / acetone / 24 h / 55 °C View Scheme

Multi-step reaction with 3 steps 1: 87 percent / dioxane / 24 h / 70 °C2: 96 percent / NaIO4 / methanol; H2O / 24 h3: 95 percent / AcOH / toluene / 4 h / 100 °C