pyridine; potassium permanganate

1: 2-methyl-1,3,5-trimethoxybenzene With potassium in tetrahydrofuran T=20°C; 24 h; 2: methyl iodide in tetrahydrofuran T=0°C; 6 h;

1: 1,3-dimethoxy-5-methyl-benzene With 2,2,6,6-tetramethyl-piperidine; n-butyllithium; potassium tert-butylate in tetrahydrofuran T=-78°C; 1 h; Inert atmosphere; 2: methyl iodide in tetrahydrofuran T=-78°C; 0.5 h; Inert atmosphere; regioselective reaction;

potassium 1.) THF, rt, 24 h; 2.) 0 deg C, 4 h; Yield given. Multistep reaction;

1: pyridine; aqueous potassium permanganate solution View Scheme