toluene-4-sulfonic acid in benzene Heating;

1: 70 percent / diisobutylaluminum hydride (DIBAL-H) / CH2Cl2 / -78 °C 2: 83 percent / lithium diisopropylamide / tetrahydrofuran / 0 °C 3: 78 percent / 20percent aq. H2SO4 / diethyl ether / Ambient temperature 4: 2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulfide (Lawesson's reagent) / toluene / Heating 5: MeCO3H / Ambient temperature 6: 70 percent / p-TsOH / toluene / Heating 7: 87 percent / m-chloroperbenzoic acid (MCPBA) / CH2Cl2 / Ambient temperature 8: 44 percent / LiOMe / methanol; tetrahydrofuran / Ambient temperature View Scheme