Esters of Carboxylic Acids 17.5 Naming Esters 17.6 Properties of Esters Chapter 17 Carboxylic Acids And Esters

2  In an ester, the H in the carboxyl group is replaced by an alkyl group. O  CH 3 —C—O—CH 3 CH 3 —COO—CH 3 ester group Esters

3 An ester is produced by the reaction of a carboxylic acid and alcohol in the presence of an acid catalyst. O  H + CH 3 —C—OH + HO—CH 2 —CH 3 O  CH 3 —C—O—CH 2 —CH 3 + H 2 O Esterification

4 Ester Products Aspirin: Is used to relieve pain and reduce inflammation. Is an ester of salicylic acid and acetic acid. Oil of wintergreen: Is used to soothe sore muscles. Is an ester of salicylic acid and methanol.

5 Esters are named with the alkyl name of the alcohol followed by the carboxylate name from the acid. from acid from alcohol O  methyl CH 3 —C—O—CH 3 Ethanoate methyl ethanoate (IUPAC) (Acetate)methyl acetate (common) Naming Esters

6  Esters give fruits their pleasant fragrances and flavors. Some Esters In Nature

7 In hydrolysis: An ester reacts with water to produce a carboxylic acid and an alcohol. An acid catalyst is required. O  H + H—C—O—CH 2 —CH 3 + H 2 O O  H—C—OH + HO—CH 2 —CH 3 Hydrolysis

8 In base hydrolysis or saponification, an ester reacts with a strong base to produce the salt of the carboxylic acid and an alcohol. O || CH 3 —C—O—CH 2 —CH 3 + NaOH O  CH 3 —C—O – Na + + HO—CH 2 —CH 3 salt of carboxylic acid alcohol Base Hydrolysis (Saponification)

9 Base Hydrolysis of Fatty Acids Produces Soaps

10 Cleaning Action of Soap A soap: Contains a nonpolar carbon end that dissolves in nonpolar fats and oils, and a polar end that dissolves in water. Forms groups of soap molecules called micelles that dissolve in water and are washed away.