* LiAlH 4 is a nucleophilic reducing agent since the hydride transfer to the carbonyl carbon occurs prior to the coordination to the carbonyl oxygen. Since $\ce{H-}$ is a strong base it should immediately abstract a proton from the carboxylic acid to give the corresponding carboxylate ion (just like in the reaction of carboxylic acids with Grignard reagents), instead of undergoing nucleophilic addition to give the alcohol. $\ce{LiAlH4}$ produces $\ce{H-}$. Carboxylic acids and esters are less reactive to Nu than aldehydes or ketones; As a result they can only be reduced by LiAlH 4 but NOT by the less reactive NaBH 4; Each reaction requires that 2 hydrides (H-) be added to the carbonyl of acids or esters; Related Reactions Carboxylic acids can be converted to 1 o alcohols using Lithium aluminium hydride (LiAlH 4). The reduction of a carboxylic acid. The simplest method of preparation is the Fischer method, in which an alcohol and an acid are reacted in an acidic medium.The reaction exists in an equilibrium condition and does not go to completion unless a product is removed as fast as it forms. Reduction to alcohols [LiAlH4] Reduction to alcohols [LiAlH 4] Definition:. 1024 CHAPTER 21 • THE CHEMISTRY OF CARBOXYLIC ACID DERIVATIVES The reaction of LiAlH 4 with an amide differs from its reaction with an ester. Addition of lithium aluminum hydride to esters leads to the formation of primary alcohols (after addition of acid).. Carboxylic acids can be converted to 1 o alcohols using Lithium aluminum hydride (LiAlH 4). It reacts faster with electron deficient carbonyl groups. Esters give a alcohol compounds mixture with LiAlH 4. Summary. Their Lewis acid qualities may be attributed not only to the acidic proton, but also to the electrophilic carbonyl carbon, as they are both able to act as an electron acceptor.

An aldehyde is produced as an intermediate during this reaction, but it cannot be isolated because it is more reactive than the original carboxylic acid.

An aldehyde is produced as an intermediate during this reaction, but it cannot be isolated because it is more reactive than the original carboxylic acid.

NaBH 4; H 2 / Ni; Na / ethanol

If amide reduction were strictly analogous to ester reduction, the nitrogen would be lost, and a primary alcohol would Note that NaBH 4 is not strong enough to convert carboxylic acids or esters to alcohols. In the reduc-tion of an ester, the carboxylate oxygen is lost as a leaving group. Carboxylic acids are both Brønsted acids and Lewis acids. Note that NaBH 4 is not strong enough to convert carboxylic acids or esters to alcohols. Reaction type: Nucleophilic Acyl Substiution then Nucleophilic Addition.