Reductions of Carboxylic Acid Derivatives to Alcohols or Amines

3 Reductions of Carboxylic Acid Derivatives to Alcohols or Amines 

Complex or soluble neutral metal hydrides are usually employed for the reduction of carboxylic acid derivatives to alcohols or amines. The standard reagents for the most important transformations are shown in Table 17.6. For completeness, various reagents also are listed for the reduction of carboxylic acid derivatives to aldehydes. The latter mode of reduction was discussed in Section 6.5.2. 

Products of the Reduction of Nitriles with LiAlH4 and DIBAL 

It is noteworthy that all of the latter reductions yield amines rather than alcohols. This is due to the favored decomposition path of the initially formed tetrahedral intermediates. 

Specifically, the tetrahedral intermediates B and D are formed in amide reductions with LiAlH4 and DIBAL, respectively. Their decomposition in principle could affect the C—O bond (— — — amine) or the C—N bond (— — — alcohol). There are two factors that provide an advantage for the C—O bond cleavage  

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