Fundamentals of Organic ChemistryChemistryGeneral Organic Chemistry
Which of the following molecules are chiral? (i) (ii) (iii)
Options
- A(i) and (iii)
- B(i) and (ii)
- C(ii) and (iii)
- D(i), (ii) and (iii)
Correct answer
A. (i) and (iii)
Step-by-step solution
To determine if a molecule is chiral, we need to check for the presence of a plane of symmetry (POS) or a center of symmetry (COS). Molecules lacking both (and more generally, any alternating axis of symmetry S_n ) are chiral. 1. Molecule (i) is trans-1,2-dimethylcyclobutane. One methyl group is pointing towards the viewer (wedge) and the other is pointing away (dash). This molecule lacks both a plane of symmetry and a center of symmetry. It only possesses a C₂ axis of symmetry. Therefore, it is a chiral molecule a