In which of the following molecules is the C atom marked with an asterisk (*) chiral? (See structures I–IV in the figure.)(I)(II)(III)(IV)
(A)I, II, III✓ Correct
(B)I, II, III, IV
(C)II, III, IV
(D)I, III, IV
Answer: (A)
Solution
A carbon is chiral when its four substituents are all different. I: C* bears H, Cl, Br, CH3 — all different → chiral. II: C* bears H, Cl, Br, I — all different → chiral. III: C* bears H, OH, CH3, C2H5 — all different → chiral. IV: C* bears H, CH3, CH3 and one more group — two identical methyls → not chiral. Hence I, II and III are chiral: option (A).
CBSE Class 12 Board · 2024 · Single correct option
