Question

Assertion (A) Commercially acids are reduced to alcohols by converting them to the esters followed by their reduction using catalylic hydrogenation.
Reason (R) $LiAlH _{4}$ can also reduce carboxylic acids to primary alcohols but $LiAlH _{4}$ is an expensive reagent and used for preparing special chemicals only.

• A. Both A and $R$ are correct; $R$ is the correct explanation of $A$.
• B. Both A and $R$ are correct; $R$ is not the correct explanation of $A$.
• C. $A$ is correct; $R$ is incorrect.
• D. $R$ is correct; $A$ is incorrect.

Answer 1

Answer: (B)

Carboxylic acids are reduced to the primary alcohols in excellent yields by lithium aluminium hydride, a strong reducing agents.
$R COOH \xrightarrow[ (ii) H _{2} O ]{(i) LiAlH _{4}}R CH _{2} OH$
$LiAlH _{4}$ is an expensive reagent and therefore, used for preparing special chemicals only.Commercially, acids are reduced to alcohols by converting them to esters followed by their reduction using hydrogen in the presence of catalyst.
$R COOH \xrightarrow[ H ^{+}] {R' OH } R COOR' \xrightarrow[\text { catalyst }]{ H _{2}} R CH _{2} OH +R' OH$