1-[2-(2-oxopyrrolidin-1-yl)ethyl]pyrrolidin-2-one

3,3-二氯二氢呋喃-2(3H)-酮

(Z)-3-(4-methoxybenzylidene)dihydrofuran-2(3H)-one

3-[(4-nitrophenyl)methylidene]oxolan-2-one

3-[(3,4,5-trimethoxyphenyl)methylidene]oxolan-2-one