The molecule is a carboxy-2-hydroxymuconate semialdehyde having the carboxy group at the 4-position and the aldehyde functijon at the 6-position. It is a conjugate acid of a 4-carboxy-2-hydroxy-cis,cis-muconate 6-semialdehyde(2-).
(E)-2-[(E)-2-hydroxyethenyl]-4-oxopent-2-enedioic acid