1: potassium hydroxide / water / 7.5 h / |Reflux 2: acetic anhydride / 1,3,5-trimethyl-benzene / 1 h / 100 °C / 150.01 Torr 3: pyridine / dichloromethane / 0 - 20 °C 4: tetrahydrofuran; diethyl ether / 2 h / -75 °C 5: hydrogenchloride / water; 1,3,5-trimethyl-benzene / 1 h / |Reflux 6: sodium methylate / tetrahydrofuran; methanol / 6 h / 20 °C View Scheme