(2E)-2-hydroxypenta-2,4-dienoate => 2-oxopent-4-enoate
(2e)-2-hydroxypenta-2,4-dienoate => 2-oxopent-4-enoate
(2E)-2-hydroxypenta-2,4-dienoate => 2-oxopent-4-enoate
(2e)-2-hydroxypenta-2,4-dienoate => 2-oxopent-4-enoate