ethyl 6-oxohex-2-enoate

(E,Z)-octa-2,6-dienedioic acid diethyl ester

ethyl 5,5-dimethylhexa-2,3-dienoate

(乙氧基羰基甲基)三苯基溴化膦

ethyl 2-(2-bromo-1,3-dioxo-2,3-dihydro-1H-inden-2-yl)-2-(triphenylphosphoranylidene)acetate