Question

Match the structures in Column I with their correct IUPAC names given in Column II.

• A. \(A = Q,\; B = P,\; C = S,\; D = R\)
• B. \(A = R,\; B = S,\; C = Q,\; D = P\)
• C. \(A = S,\; B = R,\; C = Q,\; D = P\)
• D. \(A = S,\; B = R,\; C = P,\; D = Q\)

Hint:

While matching structures with IUPAC names, first identify the principal functional group, then choose the parent chain, assign lowest possible locants, and finally name the substituents alphabetically.

Answer 1

The Correct Option is B

Step 1: Identify structure A.
Structure A contains a benzene ring having a propanoic acid side chain and an isobutyl group at para position.
The parent chain is propanoic acid, and the benzene ring is attached at carbon-2.
The para substituent on the phenyl ring is isobutyl.
Therefore, structure A is:
\[ \text{2-(4-isobutylphenyl)propanoic acid} \] So,
\[ A = R \]

Step 2: Identify structure B.
Structure B contains three carboxylic acid groups and one hydroxyl group.
The parent chain is propane with carboxylic acid groups at positions 1, 2, and 3.
A hydroxyl group is also present at position 2.
Therefore, the correct IUPAC name is:
\[ \text{2-Hydroxy-1,2,3-propanetricarboxylic acid} \] So,
\[ B = S \]

Step 3: Identify structure C.
Structure C contains two terminal aldehyde groups.
The parent chain contains six carbon atoms with aldehyde groups at both ends.
Two bromine atoms are present at positions 2 and 3.
Therefore, the correct IUPAC name is:
\[ \text{2,3-Dibromohexanedial} \] So,
\[ C = Q \]

Step 4: Identify structure D.
Structure D contains a phenyl group attached to a pentane chain.
The parent chain is pentane.
The phenyl group is attached at carbon-1, and bromine atoms are attached at carbon-2 and carbon-3.
Therefore, the correct IUPAC name is:
\[ \text{2,3-Dibromo-1-phenylpentane} \] So,
\[ D = P \]

Step 5: Combine all matched pairs.
From the above identification:
\[ A = R \] \[ B = S \] \[ C = Q \] \[ D = P \]

Step 6: Match with the options.
The option containing the matching:
\[ A = R,\; B = S,\; C = Q,\; D = P \] is option (B).

Step 7: Final Answer.
Thus, the correct matching is:
\[ \boxed{A = R,\; B = S,\; C = Q,\; D = P} \] Hence, the correct answer is option (B).