91120-90-0Relevant articles and documents
Dehydration Reactions with Gallic Acid Esters
Mayer, Walter,Hoffmann, Edmund H.,Loesch, Norbert,Wolf, Hans,Wolter, Burkhard,Schilling, Gerhard
, p. 929 - 938 (2007/10/02)
Gallic acid methylester (1) is oxidized by horseradish peroxidase giving the benzotropolone compound 3 and dimethyl 3,3',4,4',5,5'-hexahydro-2,2'-diphenate (2) which easily forms ellagic acid (4).By the analogous reaction with the gallic acid esters of ethanediol, 1,3-propanediol, 1,4-butanediol, trans-1,2-cyclohexanediol, 3,6-digalloylglucose, and pentagalloylglucose only 4 is formed.Oxidation of 1 by air in alkaline medium yields 4 and the 1-benzofuran derivative 9.If 9 is treated with alkali the furan ring is opened to give an intermediate from which the acconitic acid derivative 11 or the naphthalene system 12 or the benzoxepine compound 14 are obtained.By oxidation of 1 with iron(III)chloride the furan 15 is obtained.