Chemistry - STEREO ISOMERISM Question with Solution | TestHub
Which at the following is/are capable of showing geometrical as well as optical isomerism ?
Options:(select one or more)
Answer:
Solution:
Explain Question:
The objective is to identify which chemical structures exhibit both Geometrical Isomerism (restricted
rotation) and Optical Isomerism (chirality/lack of symmetry).
Concept:
Geometrical Isomerism, Optical Isomerism, Chiral Center, Atropisomerism, Pseudo-asymmetry.
Solution:
Structure 1: The exocyclic double bond allows for E/Z (geometrical) forms because the ring is
unsymmetrical. The C3 carbon is a Chiral Center, making it optically active.
Structure 2: While it shows Geometrical Isomerism at the C=C bond, the carbon is bonded to two
identical methyl groups (Me and CH3), meaning it lacks a Chiral Center. No optical isomerism.
Structure 3: The side-chain alkene shows Geometrical Isomerism. The bulky ortho-substituents on the
biphenyl rings prevent rotation (Atropisomerism), creating a non-superimposable mirror image (optical).
Structure 4: The substituents on the 6-membered ring can be Cis or Trans (geometrical). The trans-form
lacks a plane of symmetry, making it Optically Active.
Final Answer: Options (A, C, and D)