“…The acids with a higher prevalence in lignin oxidation are succinic (SA), malic (MAL), and maleic acids (MA), with small amounts of fumaric (FA) and tartaric (TA) acids. Most of these acids are currently used in food, pharmaceutical, and polymer industries, as well as chemical precursors for 1,4-butanediol, tetrahydrofuran, and γ-butyrolactone [ 13 , 14 , 15 , 65 , 66 , 67 , 68 , 69 , 70 ]. In the last 15 years, several authors have studied C 4 -DCA from lignin and lignin model compounds under catalytic and non-catalytic conditions, using different strong oxidants, i.e., O 2 , O 3 , H 2 O 2, and peracetic acid.…”