ethyl 5-(4-nitrophenyl)-3-oxopent-4-enoate

(Z)-5-(4-Nitro-phenyl)-3-oxo-pent-4-enoic acid ethyl ester

ethyl 6-methyl-3-oxohept-4-enoate

(Z)-6-Methyl-3-oxo-hept-4-enoic acid ethyl ester

ethyl 2-hydroxy-5-(2-hydroxybenzoyl)benzoate