1: methyl (3-chloropropyl)-ether With magnesium; iodine in tetrahydrofuran Heating / reflux; 2: boric acid trimethyl ester in tetrahydrofuran T=0 - 65°C; 1 h; 3: 2,3-dimethylbutane-2,3-diol With sulfuric acid more than 3 stages;

in toluene T=20°C; 10 h;