1.1: trifluoroacetic anhydride / dichloromethane / 0.17 h / 0 °C 1.2: 20 °C 2.1: sodium methylate / methanol; dichloromethane / 0.5 h 3.1: potassium carbonate; tetrabutylammomium bromide / chloroform; water / 1 h / 50 °C 3.2: 24 h / 50 °C 4.1: 10 Pd/C; acetic acid; hydrogen / ethyl acetate / 4 h / 760.05 Torr 5.1: sodium methylate / methanol; dichloromethane / 0.5 h View Scheme