Question

The intermediate compound ‘X’ in the following chemical reaction is

• A.
• B.
• C.
• D.

Answer 1

The Correct Option is B

The given reaction describes the oxidation of a toluene derivative to a benzaldehyde using a reagent known as the Collins reagent, which is chromium(VI) oxide dichloride (CrO₂Cl₂) in carbon disulfide (CS₂) as solvent.

Let's analyze the reaction step by step:

1. The starting compound is toluene (methylbenzene). The Collins reagent oxidizes the methyl group directly attached to the aromatic ring to a carbonyl group (aldehyde). The proposed intermediate in this reaction is a complex where the methyl group oxygenates to form a chromate ester intermediate.
2. The intermediate compound 'X' in such reactions can be depicted as the chromate ester of toluene before undergoing hydrolysis.
3. Finally, hydrolysis of the chromate ester produces benzaldehyde.

Considering the choices given for intermediate 'X', the correct one is as follows because it typically represents a structure where the methyl group has been partially oxidized, possibly forming a chromate ester:

This is the most likely intermediate formed when using the Collins reagent in this oxidation process, as it represents the step where the chromium reagent interacts with the methyl group.