1: With diethyl methoxy borane in tetrahydrofuran; methanol T=-78°C; 0.583333 h; 2: With sodium tetrahydroborate in tetrahydrofuran; methanol T=-78°C; 3 - 4 h; 3: With acetic acid in tetrahydrofuran; methanol; water; ethyl acetate T=-78 - 28°C; 0.166667 h;