In the given reaction

(Where Et is $$-C_2H_5$$)
The number of chiral carbon(s) in product A is ______.

The molecule contains both a ketone and an ester group.

In presence of ethoxide $$\mathrm{(-OEt)}$$, the reaction proceeds through an intramolecular Claisen condensation.

The base removes the most accessible acidic $$\mathrm{\alpha}$$-hydrogen from the terminal methyl group $$\mathrm{(-CH_3)}$$ adjacent to the ketone.

This pathway is favoured because it forms a stable six-membered ring instead of a strained four-membered ring.

The resulting enolate attacks the ester carbonyl carbon, followed by elimination of the ethoxy group.

This produces a fused bicyclic $$\mathrm{\beta}$$-diketone system.

The only chiral carbons present are the two bridgehead carbons where the rings are fused.

All remaining carbons are either:

$$\mathrm{sp^2}$$

hybridised carbonyl carbons or methylene carbons containing identical hydrogens.

Hence, the number of chiral carbons in product $$\mathrm{A}$$ is:

$$\mathrm{2}$$

Correct Answer: $$\mathrm{2}$$