Question

The following synthetic routes are incorrect. What is wrong with each?

Short answer

1. The reagent path is incorrect.
2. Aryl halides cannot participate in S_N2 reactions.
3. The product formed is incorrect.

Step-by-step solution

 Step 1: Reaction (a)

The synthetic route for reaction (a) is wrong.

The given reagents are used in this reaction to carry out bromination for the carbonyl compound. Esters do not undergo bromination with the given reagents.

Reaction (b)

The synthetic route for reaction (b) is wrong.

In this reaction, an anion forms an anion of a proton from the reactant (diethyl-2-methyl malonate) by the given base.

In the second step, the anion will attack the phenyl bromide, which is impossible. The nucleophilic attack is impossible on aryl halides because of the double bond between carbon and halide.

Reaction (c)

The synthetic route for the reaction (c) is wrong.

The correct sequence and the final product for the given reaction is,

Product formed in reaction (c)