2-(3-nitrophenylamino)-3-oxobutanoic acid ethyl ester

乙基5-异丙基-3-甲基-6-氧代-1,6-二氢-2-吡嗪羧酸酯

ethyl 2-ethoxy-3-oxobutanoate

ethyl 2-(acetylhydrazinylidene)-3-oxobutanoate

2-diazonio-1-ethoxy-3-trimethylsilyloxybuta-1,3-dien-1-olate