马来酰亚胺

acetic acid 5-oxo-2,5-dihydro-1H-pyrrol-2-yl ester

tert-butyl 2-hydroxy-5-oxo-2,5-dihydro-1H-pyrrole-1-carboxylate

吡咯

5-甲氧基呋喃-2(5h)-酮