methyl (9E,11Z)-8,13-dioxotrideca-9,11-dien-5-ynoate

methyl 8-hydroxyoct-5-ynoate

methyl 8-chloro-8-oxooct-5-ynoate

8-methoxy-8-oxooct-3-ynoate

1-diazonio-9-methoxy-9-oxonon-1-en-4-yn-2-olate