Chemistry - STEREO ISOMERISM Question with Solution | TestHub

Ans. (B) Center of inversion.

Sol. In this 1,3-diphenylcyclobutane-2,4-dicarboxylic acid the Ph (up) and Ph (down) lie at diagonally opposite corners, as do the two COOH groups. Inversion through the ring centre maps each group onto an identical group, so the molecule has a centre of inversion. No mirror plane is present, and the only alternating axis is S₂ (identical with the centre of inversion) - there is no S₄ axis.