2-(1-hydroxy-2-methylpropan-2-yl)-4,4-dimethyl-1,3-oxazol-5-one

3,3-dimethyl-1-phenylmethoxyazetidin-2-one

methyl 3-acetyloxy-2,2-dimethylpropanoate

diethyl-N-(β-hydroxypivaloyl)-aminomalonate

diethyl 2-(3,3-dimethyl-2-oxoazetidin-1-yl)propanedioate