(2R)-2-chloro-2,5-dihydro-5-oxofuran-2-acetate = 3-chloro-cis,cis-muconate + H(+) Aromatic compound metabolism; 3-chlorocatechol degradation. By 2,4-dichlorophenoxypropionic acid (2,4-DCPP). Different ratios of isoforms are detectable, depending on concentration of dichlorprop. Belongs to the mandelate racemase/muconate lactonizing enzyme family.