Question

What aldehyde or ketone is needed to prepare each alcohol by metal hydride reduction?

Short answer

Answer

The aldehyde or ketone needed to prepare each alcohol by metal hydride reduction is shown below:

Step-by-step solution

Step-by-Step Solution Step 1: Function of metal hydrides

Metal hydrides such as NaBH₄and LiAlH₄are powerful reducing agents that reduce an aldehyde into primary alcohol and a ketone into secondary alcohol. LiAlH₄ is more powerful than NaBH₄as it can also reduce other powerful functional groups.

Mechanism of the reducing action of metal hydrides

The M-H is polar, the hydride present in M-H acts as a nucleophile, and as a result, it can readily attack the carbonyl carbon center to yield alcohol.

Observation of the reactant

When primary alcohol is a product then the reactant should be an aldehyde; whereas, when secondary alcohol is a product then the reactant should be a ketone.