ethyl (Z)-3-(2,5-dihydroxyphenyl)sulfanylbut-2-enoate

Ethyl-(E)-β-(2,5-dihydroxyphenylthio)-crotonat

2-Butenoic acid, 3-[(1,3-dihydroxy-2-naphthalenyl)thio]-, ethyl ester, (Z)-

ethyl 3-(1,4-dihydroxynaphthalen-2-yl)sulfanylbut-2-enoate

ethyl 3-(3,6-dioxocyclohexa-1,4-dien-1-yl)sulfanylbut-2-enoate