1-异丙基-5,5-二甲基-2,3-哌嗪二酮

2,2-dimethyl-4-propan-2-yl-1,4-diazaspiro[5.5]undecan-5-one

1-isopropyl-3,3-dimethyl-1,4-diazaspiro[5.5]undecan-5-one

3-ethyl-3,5,5-trimethyl-1-propan-2-ylpiperazin-2-one

3-ethyl-4-isopropyl-3,6,6-trimethylpiperazin-2-one