3-Hydroxy-2,2,4,4-tetramethyl-3-p-tolyl-cyclobutanone

3-(4-Chloro-phenyl)-3-hydroxy-2,2,4,4-tetramethyl-cyclobutanone

3-(3-Chloro-phenyl)-3-hydroxy-2,2,4,4-tetramethyl-cyclobutanone

4-(1-Hydroxy-2,2,4,4-tetramethyl-3-oxo-cyclobutyl)-benzonitrile

3-(3-Fluoro-phenyl)-3-hydroxy-2,2,4,4-tetramethyl-cyclobutanone