Chemistry - STEREO ISOMERISM Question with Solution | TestHub
Which of the following compound does not have plane of symmetry?
Options:
Answer:
Solution:
Explain Question:
Identifying the compound that lacks an internal Plane of Symmetry (POS)
Concept:
Plane of Symmetry (POS) and Molecular Chirality.
Solution:
Option 1: A planar benzene ring has multiple symmetry planes, including the plane of the ring itself.
Option 2: In trans-1,3-dimethylcyclobutane, a plane passing through the substituted carbons (C1 and C3)
divides the molecule into two mirror-image halves.
Option 3: In cis-1,2-dimethylcyclopentane, a plane bisecting the C1–C2 bond and passing through the
opposite carbon (C4) acts as a POS.
Option 4: In trans-1,2-dichlorocyclobutane, the substituents are on opposite sides at adjacent carbons. No plane can divide this into mirror-image halves, making it chiral and lacking a POS.
Calculation:
Option 1: Planar structure → POS exists.
Option 2: Vertical plane through C1 and C3 → POS exists.
Option 3: Bisecting plane through C4 and C1–C2 bond → POS exists.
Option 4: trans-1,2-disubstitution → No internal plane yields mirror images.
Final Answer: Option (D)