3-ethylidene-1,4-dimethyl-3-oxo-1,2,3,4-tetrahydroquinoxaline

2,2-二甲基环戊酮

2,5-二甲基-环戊酮

2,4-二甲基环戊烷-1-酮

2-(4-methyl-6,7-dihydro-5H-1-benzothiophen-4-yl)propanedinitrile