Reduction with NaBH4 or LiAlH4 of an aldehyde yields which product?

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Multiple Choice

Reduction with NaBH4 or LiAlH4 of an aldehyde yields which product?

Reducing an aldehyde with hydride donors adds a hydride to the carbonyl carbon and a proton to the oxygen, turning the C=O into an C–OH group. In an aldehyde, the carbonyl carbon is attached to one hydrogen and one R group. After reduction, that carbon becomes part of a CH2OH group, giving the primary alcohol R–CH2OH. Both NaBH4 and LiAlH4 deliver hydride and drive this transformation, with NaBH4 being milder and LiAlH4 stronger, but yielding the same primary alcohol product. The other options don’t fit because reduction of the carbonyl does not give an ether, and reducing an aldehyde to a carboxylic acid would require a different, typically more extreme pathway.

Reducing an aldehyde with hydride donors adds a hydride to the carbonyl carbon and a proton to the oxygen, turning the C=O into an C–OH group. In an aldehyde, the carbonyl carbon is attached to one hydrogen and one R group. After reduction, that carbon becomes part of a CH2OH group, giving the primary alcohol R–CH2OH. Both NaBH4 and LiAlH4 deliver hydride and drive this transformation, with NaBH4 being milder and LiAlH4 stronger, but yielding the same primary alcohol product. The other options don’t fit because reduction of the carbonyl does not give an ether, and reducing an aldehyde to a carboxylic acid would require a different, typically more extreme pathway.

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