Reduction of an aldehyde produces a
carboxylic acid.
secondary alcohol.
ketone.
tertiary alcohol.
primary alcohol.
The Correct Answer and Explanation is :
The correct answer is: primary alcohol.
When an aldehyde is reduced, it gains hydrogen atoms, which results in the formation of a primary alcohol. This process is a fundamental type of reaction in organic chemistry, known as reduction.
Reduction reactions involve the addition of hydrogen to a molecule or the removal of oxygen. In the case of aldehydes, the carbonyl group (C=O) is the functional group that undergoes reduction. The structure of an aldehyde features a carbon atom double-bonded to an oxygen atom and single-bonded to a hydrogen atom, along with another carbon chain or a hydrogen. This carbon is the key site for reduction.
The mechanism typically involves a hydride ion (H⁻) or a hydrogen molecule (H₂) being added to the carbon in the carbonyl group of the aldehyde. This addition breaks the double bond between the carbon and oxygen, resulting in a single bond. Consequently, another bond to a hydrogen atom is formed, converting the C=O group into a C-OH group. The oxygen now bears only a single bond with the carbon and holds onto the hydrogen atom, forming a hydroxyl group (OH).
The overall effect of this reduction is the transformation of the carbonyl group into a hydroxyl group, thus changing the aldehyde into a primary alcohol. Primary alcohols are characterized by the presence of the hydroxyl group connected to a carbon atom that is also bonded to only one other carbon atom or hydrogen (indicating it’s at the end of a carbon chain), which distinguishes them from secondary and tertiary alcohols where the carbon with the OH group is bonded to two or three other carbons, respectively.
This reaction is widely used in the laboratory and industrial synthesis of alcohols from aldehydes, employing common reducing agents such as sodium borohydride (NaBH₄) or lithium aluminum hydride (LiAlH₄). These agents effectively donate hydride ions to the aldehyde, facilitating the reduction process.
Let’s generate an image to illustrate the reduction of an aldehyde to a primary alcohol.
Here is the illustration showing the chemical reaction of reducing an aldehyde to a primary alcohol. The image depicts a step-by-step reaction mechanism, detailing how hydrogen atoms are added to the aldehyde’s carbonyl group, resulting in the formation of a primary alcohol with a hydroxyl group. This visual aids in understanding the transition from the carbonyl group to the hydroxyl group during the reduction process.
