Case: Read the passage and answer the following questions

Alcohol can be prepared in many ways. Alcohols are prepared from alkenes by acid catalysed hydration and by hydroboration–oxidation. Alcohols are even prepared from ketones and aldehydes by reduction. The reduction of carboxylic acid and ester leads to the formation of alcohol. Alcohols are produced by the reaction of Grignard reagents with aldehydes and ketones. Phenol, also known as carbolic acid, was first isolated in the early nineteenth century from coal tar. Nowadays, phenol is commercially produced synthetically. In the laboratory, phenols are prepared from benzene derivatives in many ways.

Which of the following reducing agent is used in reduction of carboxylic acids and esters?

Lithium aluminium hydride

The correct answer is option 1. Lithium aluminium hydride.

The reducing agent commonly used for the reduction of carboxylic acids and esters to their corresponding alcohols is lithium aluminium hydride \((LiAlH_4)\).

Lithium Aluminium Hydride \((LiAlH_4)\):

\(LiAlH_4\) is a very strong reducing agent. It is capable of reducing carboxylic acids, esters, aldehydes, ketones, and other carbonyl-containing compounds to their corresponding alcohols. The reduction involves the transfer of hydride ions \((H^-)\) from \(LiAlH_4\) to the carbonyl carbon, ultimately reducing it to an alcohol.

Reduction Reactions:

1. Carboxylic Acids to Primary Alcohols:

2. Esters to Primary Alcohols:

Other Options:

Sodium Hydride (NaH): Sodium hydride is a strong base and is not typically used as a reducing agent for carboxylic acids or esters.

Calcium Hydride (CaH₂): Calcium hydride is also mainly used as a drying agent and is not effective for reducing carboxylic acids or esters to alcohols.

None of These: This option is incorrect because lithium aluminium hydride is indeed a suitable reducing agent for this purpose.

Conclusion: The correct reducing agent for the reduction of carboxylic acids and esters to alcohols is: Lithium aluminium hydride