Aldehyde 3:

Problem

Solution

Sodium borohydride (NaBH₄) is a reducing agent that is reasonably stable in ethanol and water. Methanol can be used as a solvent but it reacts faster with NaBH₄ than does ethanol or water. NaBH₄ reduces aldehydes to primary alcohols and ketones to secondary alcohols. Each of the the four hydride of NaBH₄ is available for reduction. In this instance, cyclohexylmethanol 2 is the product of reduction of cyclohexanecarboxaldehyde 1. What other reducing agent is available for the reaction ?