What is the product of reducing benzaldehyde with NaBH4?

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Multiple Choice

What is the product of reducing benzaldehyde with NaBH4?

Reducing an aldehyde with a mild reducing agent like NaBH4 adds a hydride to the carbonyl carbon, forming a tetrahedral alkoxide that is then protonated to give a primary alcohol. For benzaldehyde, this means the carbonyl group (the C=O) is turned into a CH2OH group, giving benzyl alcohol (Ph-CH2OH). The other options don’t fit this reduction: benzaldehyde would be the reactant, benzoic acid would come from oxidation, and benzene would require removing the oxygen entirely—something NaBH4 doesn’t do. So the product is benzyl alcohol.

Reducing an aldehyde with a mild reducing agent like NaBH4 adds a hydride to the carbonyl carbon, forming a tetrahedral alkoxide that is then protonated to give a primary alcohol. For benzaldehyde, this means the carbonyl group (the C=O) is turned into a CH2OH group, giving benzyl alcohol (Ph-CH2OH). The other options don’t fit this reduction: benzaldehyde would be the reactant, benzoic acid would come from oxidation, and benzene would require removing the oxygen entirely—something NaBH4 doesn’t do. So the product is benzyl alcohol.

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