Chloromuconic acid

The fate of the ring structure in soils has also been studied. Detection of 2,4-dichlorophenol, 4-chlorocatechol, and chloromuconic acid (9) from either soil or pure culture studies suggests a sequence of reactions involving ring hydroxylation and cleavage and further metabolism of the open chain structure to C02. 

So far as tested, pyrocatechase shows absolute specificity for both catechol and oxygen. Protocatechuic acid and other dihydroxybenzoic acids, homogentisic acid, pyrogallol, dopa, tranf-5,6-dihydroxycyclo-hexadiene, and p-aminocatechol are among the compounds that fail to serve as oxygen acceptor with this enzyme. It has not been determined whether the 4-chlorocatechol found to be oxidized by a pseudomonad to j3-chloromuconic acid (Evans and Moss, 1957) is attacked by pyrocatechase or an analogous enzyme. 

R = Me, Et, n Pr and i-Pr ) in yields of 7 - 82 % (R = n Bu gave no reaction). 4-Methylcatechol and 3-methylcatechol afforded monomethyl methylmuconates (79 %). 4-Chlorocatechol gave the corresponding monoester of chloromuconate. Nitrocatechol and protocatechuic (3,4-dihydroxybenzoic) acid yielded no muconlc acid derivatives. 

---