toluene-4-sulfonic acid in various solvent(s) T=175°C;

1: 74 percent / diisobutylaluminum hydride / tetrahydrofuran; hexane / 1 h / -20 °C 2: 14 percent / p-toluenesulfonic acid / various solvent(s) / 175 °C View Scheme

1: 1.) 10percent aq. NaOH, 2.) 10percent aq. H2SO4 / 1.) ethanol, room temp., 5 h, 2.) reflux, 12 h 2: 74 percent / diisobutylaluminum hydride / tetrahydrofuran; hexane / 1 h / -20 °C 3: 14 percent / p-toluenesulfonic acid / various solvent(s) / 175 °C View Scheme