Identify A and B in the given chemical reaction sequence : -

CONCEPT:

Friedel-Crafts Acylation and Clemmensen Reduction

• Friedel-Crafts acylation involves the introduction of an acyl group (RCO-) into an aromatic ring using a Lewis acid catalyst like AlCl₃.
• In this reaction, the benzene ring reacts with an acyl chloride in the presence of AlCl₃ to form a ketone.
• The Clemmensen reduction then reduces the ketone to an alkyl group using Zn-Hg and HCl, converting the carbonyl group into a methylene (-CH₂-) group.

EXPLANATION:

• In the given reaction sequence, compound A is formed by the acylation of benzene with succinyl chloride in the presence of AlCl₃, yielding a diketone compound.
• Compound B is formed by the subsequent Clemmensen reduction, which reduces the carbonyl groups of the diketone to form a cyclic ketone.
• The correct structures of compounds A and B correspond to option (1) in the given question.

The correct answer is option (1).