Brønsted acidic ionic liquids catalyze the high-yield production of diphenolic acid/esters from renewable levulinic acid

The high-yielding synthesis of diphenolic acid (DPA) using Bronsted acidic ionic liquids (BAILs) has been demonstrated in this study. Importantly, p,p′-DPA was obtained as the preferential product over o,p′-DPA with an isomer ratio over 100. Moreover, diphenolic esters were also prepared in high yield through a one-pot method.