This question involves identifying the product [X] in a reaction where an aldehyde undergoes a transformation. The reaction shown is a classic example of the Cannizzaro reaction.

What is the Cannizzaro Reaction?

The Cannizzaro reaction is a chemical reaction that involves the disproportionation of an aldehyde that lacks an alpha-hydrogen atom. In a disproportionation reaction, the same substance is both oxidized and reduced.

For an aldehyde with no alpha-hydrogen (e.g., formaldehyde, benzaldehyde), when treated with a concentrated base (like NaOH or KOH), one molecule of the aldehyde is reduced to the corresponding alcohol, while another molecule is oxidized to the corresponding carboxylic acid salt.

The general reaction can be represented as:

$2 R - C (= O) H + O H -^{} \to R - C O O^{-} + R - C H_{2} O H$

Where R is an aryl group or a group with no alpha-hydrogen.

Analyzing the Given Reaction

The reactant in the image is 2,2-dimethylpropanal. Its structure is:

$(C_{H})_{3} C - C (= O) H$

This aldehyde has no alpha-hydrogens (the carbon adjacent to the carbonyl carbon is a tertiary carbon, bonded to three methyl groups). Therefore, it will undergo the Cannizzaro reaction.

Step 1: Identify the Products
In the Cannizzaro reaction, one molecule is oxidized to a carboxylate ion, and one is reduced to an alcohol.

Oxidation Product (Carboxylic Acid Salt): The carboxylate ion derived from 2,2-dimethylpropanal is 2,2-dimethylpropanoate ion, $(C_{H})_{3} C - C O O^{-}$ .
Reduction Product (Alcohol): The alcohol derived from 2,2-dimethylpropanal is 2,2-dimethylpropan-1-ol, $(C_{H})_{3} C - C H_{2} O H$ .

Looking at the options, the structure for the alcohol product matches one of them: $(C_{H})_{3} C C H_{2} O H$ .

Final Answer

The product [X] is the alcohol, 2,2-dimethylpropan-1-ol.

Related Topics & Formulae

Key Concept: Cannizzaro Reaction
Condition: Aldehydes with no alpha-hydrogen atoms.
Mechanism: A hydride ion (H⁻) transfer from one aldehyde molecule to another, facilitated by a strong base.
General Equation:
$2 Ar - C H O + O H^{-} \to Ar - C O O^{-} + Ar - C H_{2} O H$