Chapter 17 Carboxylic Acids and Their Derivatives  Nucleophilic Addition–Elimination at the Acyl Carbon Ch. 17 - 1 1. Introduction  Carboxylic Acid Derivatives O O O O R OH R Cl R O R' carboxylic acid acid chloride acid anhydride O O R NR' R OR' 2 ester amide Ch. 17 - 2 2. Nomenclature and Physical Properties  Nomenclature of Carboxylic Acids and Derivatives ● Rules  Carboxylic acid as parent (suffix): ending with “–oic acid”  Carboxylate as parent (suffix): ending with “–oate” Ch. 17 - 3  Most anhydrides are named by dropping the word acid from the name of the carboxylic acid and then adding the word “anhydride”  Acid chloride as parent (suffix): ending with “–oyl chloride”  Ester as parent (suffix): ending with “–oate”  Amide as parent (suffix): ending with “amide”  Nitrile as parent (suffix): ending with “nitrile” Ch. 17 - 4 Examples  O O OCH OH 3 Ethanoic acid Methyl propanoate (acetic acid) O O O NH' O 2 Ethanoic anhydride Ethanamide (acetic anhydride) Ch. 17 - 5 Examples  O O Cl O Na Sodium benzoate Benzoyl chloride H C C N 3 Ethanenitrile Ch. 17 - 6 2C. Acidity of Carboxylic Acids O H R O pK ~ 4-5 a  Compare ● pK of H O ~ 16 a 2 ● pK of H CO ~ 7 a 2 3 ● pK of HF ~ 3 a Ch. 17 - 7 When comparing acidity of organic  compounds, we compare the stability of their conjugate bases. The more stable the conjugate base, the stronger the acid CH COOH CH CH OH 3 3 2 pK 4.75 16 a Ch. 17 - 8 O O + + H O + H O 2 3 CH O H CH O 3 3 A B 1 1 + CH CH O H + H O CH CH O + H O 3 2 2 3 2 3 A B 2 2 Ch. 17 - 9 The conjugate base B is more stable  1 (the anion is more delocalized) than B 2 due to resonance stabilization O O O CH O CH O CH O 3 3 3 ● Thus, A is a stronger acid than 1 A 2 Ch. 17 - 10