1: dichloromethane With n-butyllithium in tetrahydrofuran T=-100°C; Metallation; 0.166667 h; 2: 4,4,5,5-tetramethyl-2-(1-phenylethyl)-1,3,2-dioxaborolane With zinc(II) chloride in tetrahydrofuran; diethyl ether T=-100 - 20°C; Substitution; 3: With sodium chlorite in tetrahydrofuran; diethyl ether Oxidation; 48 h; Title compound not separated from byproducts;