1: 1-bromo-3-methyl-benzene With iodine; magnesium in tetrahydrofuran Reflux; 2: With copper(l) iodide in tetrahydrofuran T=0 - 20°C; 1 h; 3: glutaric acid anhydride in tetrahydrofuran T=0 - 20°C; 1.5 h;