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Ester formation
Alcohols react with carboxylic acids in a reversible reaction according to the following equation:
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ACID + ALCOHOL |
The reaction is slow, and requires a concentrated sulfuric acid catalyst. It is still necessary to reflux it for some time. Remove the OH from the acid and the H from the alcohol, then join the free ends of the molecules together:
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This reaction is called an addition-elimination reaction or condensation reaction. It is also simply referred to as an esterification reaction. A number of examples follow. Students often name them backwards, so beware! The alkyl part of the name comes from the alcohol and the alkanoate part of the name comes from the acid:
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Esters often have a fruity smell (a popular exam question) and a wide variety of esters are found in fruit. Esters are also used in fruit flavourings. Pentyl ethanoate smells of bananas. Ethyl butanoate resembles pineapple. |
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ESTER + WATER
