1: oxalic acid / tetrahydrofuran / Linde 4A molecular sieves 2: 82 percent / 1.) titanium tetrachloride, 2,4,6-trimethylpyridine, 2.) 1 M hydrochloric acid / CH2Cl2 / 1.) -78 degC, 5 min., 2.) -78 degC to r.t. 3: pyridinium chlorochromate / CH2Cl2 / 18 h / 25 °C 4: 7.5 M KOH / tetrahydrofuran; methanol; H2O / 48 h / 25 °C 5: 96 percent / 10percent DMAP / pyridine / 3 h / 70 °C 6: 89 percent / H2 / Lindlar catalyst 7: 72 percent / BF3*Et2O 8: H2 / PtO2 9: KOH / tetrahydrofuran; methanol; H2O / 48 h / 25 °C View Scheme

diisobutylaluminium hydride

3: diisobutylaluminium hydride View Scheme

2: diisobutylaluminium hydride View Scheme