1: water; sodium hydroxide / methanol / 6 h / 20 °C 2: potassium carbonate; potassium iodide / N,N-dimethyl-formamide / 6 h / 40 °C View Scheme

1.1: methanesulfonic acid; dl-methionine / 3 h / 130 °C / |Cooling with ice 1.2: pH 7 2.1: pyridine / 3 h / 20 - 100 °C 3.1: thionyl chloride / N,N-dimethyl-formamide / 3 h / 70 °C 4.1: isopropyl alcohol / 5 h / 88 °C 5.1: water; sodium hydroxide / methanol / 6 h / 20 °C 6.1: potassium carbonate; potassium iodide / N,N-dimethyl-formamide / 6 h / 40 °C View Scheme

1.1: trimethyl orthoformate / methanol / 4 h / 70 °C / |Reflux 2.1: methanesulfonic acid; dl-methionine / 3 h / 130 °C / |Cooling with ice 2.2: pH 7 3.1: pyridine / 3 h / 20 - 100 °C 4.1: thionyl chloride / N,N-dimethyl-formamide / 3 h / 70 °C 5.1: isopropyl alcohol / 5 h / 88 °C 6.1: water; sodium hydroxide / methanol / 6 h / 20 °C 7.1: potassium carbonate; potassium iodide / N,N-dimethyl-formamide / 6 h / 40 °C View Scheme

1: pyridine / 3 h / 20 - 100 °C 2: thionyl chloride / N,N-dimethyl-formamide / 3 h / 70 °C 3: isopropyl alcohol / 5 h / 88 °C 4: water; sodium hydroxide / methanol / 6 h / 20 °C 5: potassium carbonate; potassium iodide / N,N-dimethyl-formamide / 6 h / 40 °C View Scheme

1: potassium carbonate / 60 °C 2: potassium permanganate / acetone / |Reflux 3: thionyl chloride / |Reflux 4: acetic anhydride; acetic acid; nitric acid / 0 - 5 °C 5: acetic acid; iron / methanol 6: ethanol / |Reflux 7: trichlorophosphate; triethylamine / toluene / |Reflux 8: isopropyl alcohol / |Reflux View Scheme

1: potassium permanganate / acetone / |Reflux 2: thionyl chloride / |Reflux 3: acetic anhydride; acetic acid; nitric acid / 0 - 5 °C 4: acetic acid; iron / methanol 5: ethanol / |Reflux 6: trichlorophosphate; triethylamine / toluene / |Reflux 7: isopropyl alcohol / |Reflux View Scheme