tailieunhanh - Lecture Organic chemistry: Chapter 21 (part 1) - L. G. Wade, Jr.

Chapter 21 (part 1) - Structure and properties of carboxylic acid derivatives. This chapter draw and name carboxylic acid derivatives, and use spectral information to determine their structures; describe the trends in physical properties of acid derivatives, and compare the relative reactivity of esters, thioesters, amides, nitriles, anhydrides, and acid chlorides; propose single-step and multistep syntheses of acid derivatives from compounds containing other functional groups. | Chapter 21 Copyright © 2010 Pearson Education, Inc. Organic Chemistry, 7th Edition L. G. Wade, Jr. Part 1: Structure and Properties of Carboxylic Acid Derivatives Chapter 21 Acid Derivatives All the derivatives can be converted to the carboxylic acid by acidic or basic hydrolysis. Esters and amides are commonly found in nature. Chapter 21 Esters from Carboxylic Acids Esters can be made from the carboxylic acid through the Fischer esterification. Excess alcohol is used to drive the equilibrium toward the ester. Chapter 21 Nomenclature of Esters Esters are named as alkyl carboxylates. The first word is derived from the alkyl group of the alcohol, and the second word from the carboxylate group of the carboxylic acid. Chapter 21 Cyclic Esters Reaction of —OH and —COOH on same molecule produces a cyclic ester called lactone. To name, add the word lactone to the IUPAC acid name or replace the -ic acid of common name with -olactone. Chapter 21 Amide . | Chapter 21 Copyright © 2010 Pearson Education, Inc. Organic Chemistry, 7th Edition L. G. Wade, Jr. Part 1: Structure and Properties of Carboxylic Acid Derivatives Chapter 21 Acid Derivatives All the derivatives can be converted to the carboxylic acid by acidic or basic hydrolysis. Esters and amides are commonly found in nature. Chapter 21 Esters from Carboxylic Acids Esters can be made from the carboxylic acid through the Fischer esterification. Excess alcohol is used to drive the equilibrium toward the ester. Chapter 21 Nomenclature of Esters Esters are named as alkyl carboxylates. The first word is derived from the alkyl group of the alcohol, and the second word from the carboxylate group of the carboxylic acid. Chapter 21 Cyclic Esters Reaction of —OH and —COOH on same molecule produces a cyclic ester called lactone. To name, add the word lactone to the IUPAC acid name or replace the -ic acid of common name with -olactone. Chapter 21 Amide Structure Amides are the product of the reaction of a carboxylic acid with ammonia or an amine. Not basic because the lone pair on nitrogen is delocalized by resonance. The C—N bond has double-bond character. Chapter 21 Protonation of Amides Under acidic conditions, the double-bonded oxygen will get protonated. Chapter 21 Classes of Amides 1 amide has one C—N bond (two N—H). 2 amide or N-substituted amide has two C—N bonds (one N—H). 3 amide or N,N-disubstituted amide has three C—N bonds (no N—H). 3º amide 2º amide 1º amide Chapter 21 Nomenclature of Amides For 1 amide, drop -ic or -oic acid from the carboxylic acid name, add -amide. Alkyl groups bonded to nitrogen are named with N-alkyl to indicate their attachment to the nitrogen atom. N-ethyl-N-methyl-2-dimethylpropanamide (N-ethyl-N-methylisobutyramide) C H 3 C H C N O C H 2 C H 3 C H 3 C H 3 Chapter 21 Cyclic Amides Cyclic amides are called lactams. To name, add the word lactam to the IUPAC acid