The molecule is a 4-(3-hydroxy-1-benzothiophen-2-yl)-2-oxobut-3-enoic acid in which the acyclic double bond has Z-geometry. It is a conjugate acid of a cis-4-(3-hydroxy-1-benzothiophen-2-yl)-2-oxobut-3-enoate.
(Z)-4-(3-hydroxy-1-benzothiophen-2-yl)-2-oxobut-3-enoic acid