1: 65 percent / diisobutylaluminum hydride / toluene; hexane / 0.5 h / -70 °C 2: 81.2 percent / p-toluenesulfonic acid / acetone / 4 h / Ambient temperature 3: 83 percent / CrO3, pyridine / CH2Cl2 / 0.5 h / Ambient temperature 4: 28 percent / diisopropylamine, n-butyllithium, HMPT / tetrahydrofuran; hexane / 1.) -45 deg C, 15 min, 2.) -45 deg C, 2 h; r.t., 30 min 5: 2.) aq. HCl, FeCl3 / 1.) toluene, 270 deg C, 30 min, 2.) MeOH, 3 h View Scheme