1: benzhydryliden-(4-bromo-2-methoxyphenyl)-amine With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 1 h; 2: boric acid trimethyl ester in tetrahydrofuran; hexane T=-85°C; 1 h; 3: 2,3-dimethylbutane-2,3-diol With sodium hydroxide; sulfuric acid more than 3 stages;