1: 1.) trimethylsilyl chloride / 1.) pyridine, RT, 15 min, 2.) pyridine, RT, 2 h 2: 77 percent / 70percent HClO4 / 3 h / Ambient temperature 3: BaMnO4 / 1,2-dichloro-ethane / 3 h / Heating 4: 54 percent / CH2Cl2; hexane / 2 h / -75 °C 5: 1.) 90percent aq. HCOOH, 2.) NH4OH / 1.) 6 h, 2.) dioxane, RT, 6 h View Scheme

1: 54 percent / CH2Cl2; hexane / 2 h / -75 °C 2: 1.) 90percent aq. HCOOH, 2.) NH4OH / 1.) 6 h, 2.) dioxane, RT, 6 h View Scheme

1: 77 percent / 70percent HClO4 / 3 h / Ambient temperature 2: BaMnO4 / 1,2-dichloro-ethane / 3 h / Heating 3: 54 percent / CH2Cl2; hexane / 2 h / -75 °C 4: 1.) 90percent aq. HCOOH, 2.) NH4OH / 1.) 6 h, 2.) dioxane, RT, 6 h View Scheme

1: BaMnO4 / 1,2-dichloro-ethane / 3 h / Heating 2: 54 percent / CH2Cl2; hexane / 2 h / -75 °C 3: 1.) 90percent aq. HCOOH, 2.) NH4OH / 1.) 6 h, 2.) dioxane, RT, 6 h View Scheme

1: 1.) 15-crown-5, NaH / 1.) DMF, RT, 1 h, 2.) DMF, 80 deg C, 2 h 2: 91 percent / HCl / ethanol / 15 h / Ambient temperature View Scheme

ammonium hydroxide; formic acid 1.) 6 h, 2.) dioxane, RT, 6 h; Multistep reaction;