4-(((R)-1-((R)-2-((tert-butyldimethylsilyl)oxy)-1-phenylethyl)-4,4-dimethyl-2-oxopyrrolidin-3-yl)oxy)-2-(difluoromethyl)benzonitrile

(R)-4-((1-(2-((tert-butyldimethylsilyl)oxy)ethyl)-4,4-dimethyl-2-oxopyrrolidin-3-yl)oxy)-3-methoxybenzonitrile

(R)-6-((1-benzyl-4,4-dimethyl-2-oxopyrrolidin-3-yl)oxy)nicotinonitrile

(R)-3-hydroxy-4,4-dimethyl-1-((3-methyl-1,2,4-oxadiazol-5-yl)methyl)pyrrolidin-2-one

(R)-1-((R)-2-((tert-butyldimethylsilyl)oxy)-1-phenylethyl)-3-hydroxy-4,4-dimethylpyrrolidin-2-one