(2R,5S)-2,5-bis[[4-(dimethylamino)phenyl]methyl]-3-methylimidazolidin-4-one;(2R,5S)-2,5-bis[(4-methoxyphenyl)methyl]-3-methylimidazolidin-4-one;(2R,5S)-3-methyl-2,5-bis[(4-nitrophenyl)methyl]imidazolidin-4-one;(2R,5S)-3-methyl-2,5-bis(2-phenylethyl)imidazolidin-4-one;(5S)-2,2,3-trimethyl-5-[(4-methylphenyl)methyl]imidazolidin-4-one;4-[[(4S)-1,2,2-trimethyl-5-oxoimidazolidin-4-yl]methyl]benzonitrile