preferred_name: 2-oxopent-4-enoate => (2E)-2-hydroxypenta-2,4-dienoate
preferred_name_lc: 2-oxopent-4-enoate => (2e)-2-hydroxypenta-2,4-dienoate
label: 2-oxopent-4-enoate => (2E)-2-hydroxypenta-2,4-dienoate
label_lc: 2-oxopent-4-enoate => (2e)-2-hydroxypenta-2,4-dienoate