In the following reaction sequence, structure of A and B respectively will be:

Step 1: Analyze the starting material

Cyclic ketone with $\ce{-CH2Br}$ side chain

Step 2: Reaction with HBr

HBr can:

• Protonate the ketone oxygen
• Add to any C=C if present
• React with $\ce{-CH2Br}$ (unlikely - already has Br)

If there's a ketone, HBr might not react directly. The structure needs clarification from the image.

Step 3: Reaction with Na/Ether (Wurtz coupling)

Wurtz reaction: $\ce{2 R-Br + 2 Na ->[Ether] R-R + 2 NaBr}$

This couples two alkyl bromides.

Intermolecular product B means two molecules couple together.

Step 4: Determine structures

Given answer (c):

• A: Product after HBr treatment (likely adds Br somewhere)
• B: Coupled product (two A molecules joined)

The reaction sequence suggests:

1. HBr adds to create more Br sites
2. Na/Ether couples the molecules

Answer: (c)

Key Reactions:

Wurtz reaction:

• Couples alkyl halides
• Uses Na metal in dry ether
• Forms C-C bond
• Intermolecular: $\ce{2 R-X -> R-R}$

Wurtz-Fittig:

• Couples aryl and alkyl halides
• $\ce{Ar-X + R-X + 2Na -> Ar-R}$

Limitations:

• Works best with primary halides
• Secondary/tertiary give elimination
• Can give mixture of products