Carboxylic acids (RCOOH) can be reduced to primary alcohols by lithium aluminum hydride (LiAlH4). This reaction is a two stages reaction. LiAlH4 is a strong reducing agent used in organic chemistry for reducing several organic compounds.
R can be a carbon group or hydrogen atom. General equation for reduction of carboxylic acid is written above.
Lithium aluminum hydride (LiAlH4) is strong reducing agent used in organic chemistry. It can be used to reduce carbonyl groups (aldehyde and ketone), carboxylic acids, esters, amides etc.
Due to reduction, oxidation number of carbon atom in the carboxylic group should be reduced.
First, carboxylic acid is reduced to an aldehyde compound. But, formed aldehyde is readily reduced to a primary alcohol by LiAlH4. So. We cannot stop at intermediate stage to get the aldehyde.
Methanol is formed when formic acid is reduced by LiAlH4
When acetic acid reacts with LiAlH4, ethanol is formed.
Carboxylic acids cannot be reduced by any of the Sodium borohydride (NaBH4) or sodium / ethanol or hydrogen gas with platinum catalyst. Their reducing power is not enough to reduce carboxylic acid.
Questions asked by students
When carboxylic acid chloride is reduced by LiAlH4, a primary amine compound is given as the product. Therefore, carboxylic acid chloride reduction and carboxylic acid chloride reduction by LiAlH4 is not similar due to giving different products.
Yes. RCOOH represents a carboxylic acid. R can be a carbon group or hydrogen. Equation can be written like this.
If carboxylic acid is reduced, something should be oxidized. Therefore, LiAlH4 is oxidized. When you study the structure of LiAlH4, you will know there are hydrogen atoms at -1 oxidation state. These hydrogen atoms can be oxidized to hydrogen gas easily than Li+ and Al3+ ions.