《有机化学》课程PPT教学课件（Official PPT of Organic Chemistry 6th LG Wade by Prentice Hall，L. G. Wade, Jr.）Chapter 21 Carboxylic Acid Derivatives

PhOCH,C -NH Organic Chemistry,6th Edition COOH L.G.Wade,Jr. acylated. inactive Chapter 21 Carboxylic Acid Derivatives Jo Blackburn Richland College,Dallas,TX Dallas County Community College District ©2006，Prentice Hall

Chapter 21 Carboxylic Acid Derivatives Jo Blackburn Richland College, Dallas, TX Dallas County Community College District © 2006, Prentice Hall Organic Chemistry, 6th Edition L. G. Wade, Jr

0 PhOCH,C- NH CH CH COOH Acid Derivatives acylated. mnactive enzyme All can be converted to the carboxylic acid by acidic or basic hydrolysis. Esters and amides common in nature. -0-R C一NH R一C=N acid halide anhydride ester amide nitrile Condensed structure:RCOX (RCO).O RCO,R' RCONH, RCN Copyright2005 Pearson Prentice Hall,Inc. Chapter 21 2

Chapter 21 2 Acid Derivatives • All can be converted to the carboxylic acid by acidic or basic hydrolysis. • Esters and amides common in nature. =>

PhOCH,C. Naming Esters COOH inactive enzyme Esters are named as alkyl carboxylates. Alky/from the alcohol,carboxylate from the carboxylic acid precursor. CH3CH2-OH+HO一 CHgCH2-O-C-CH3 H2O ethanol ethanoic acid ethyl ethanoate ethyl alcohol acetic acid ethyl acetate => Chapter 21 3

Chapter 21 3 Naming Esters • Esters are named as alkyl carboxylates. • Alkyl from the alcohol, carboxylate from the carboxylic acid precursor. CH3CH2 OH HO C O CH3 H + + CH3CH2 O C + H2O O CH3 ethanol ethyl alcohol ethanoic acid acetic acid ethyl ethanoate ethyl acetate =>

0 PhOCH C NH CH CH COOH Name These acylated. inactive enzyme CH3 0 9 CH:CHCH2OCCH3 HCOCH2 isobutyl acetate benzyl formate 2-methylpropyl ethanoate benzyl methanoate Chapter 21 4

Chapter 21 4 Name These CH3CHCH2OCCH3 CH3 O HCOCH2 O isobutyl acetate 2-methylpropyl ethanoate benzyl formate benzyl methanoate =>

PhOCH.C Cyclic Esters COOH inactive enzyme Reaction of-OH and-COOH on same molecule produces a cyclic ester,lactone. To name,add word lactone to the IUPAC acid name or replace the -ic acid of common name with -olactone. 4-hydroxy-2-methylpentanoic acid lactone a-methyl-y-valerolactone CH; 三> Chapter 21 5

Chapter 21 5 Cyclic Esters • Reaction of -OH and -COOH on same molecule produces a cyclic ester, lactone. • To name, add word lactone to the IUPAC acid name or replace the -ic acid of common name with -olactone. O O H3 C CH3 4-hydroxy-2-methylpentanoic acid lactone -methyl--valerolactone =>

PhOCH,C CH CH COOH Amides acylated. inactive enzyme Product of the reaction of a carboxylic acid and ammonia or an amine. Not basic because the lone pair on nitrogen is delocalized by resonance. :O: :0: H H H H Bond angles around N are close to120°. => Chapter 21 6

Chapter 21 6 Amides • Product of the reaction of a carboxylic acid and ammonia or an amine. • Not basic because the lone pair on nitrogen is delocalized by resonance. H C O N H H H C O N H H _ + Bond angles around N are close to 120. =>

PhOCH.C COOH Classes of Amides inactive enzyme ·1°amide has one C-N bond(woN-H). ·2°amide or N-substituted amide has two C-N bonds (one N-H) ·3°amide or M,W-disubstituted amide has three C-N bonds(no N-H) Chapter 21

Chapter 21 7 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). =>

PhOCH,C CH CH COOH Naming Amides acylated enzyme ·For1°amide,drop-icor-oic acid from the carboxylic acid name,add -amide. ·For2°and3°amides,the alkyl groups bonded to nitrogen are named with N- to indicate their position. N-ethyl-N,2-dimethylpropanamide CH:CHC-N-CH2CH3 N-ethyl-N-methylisobutyramide CH3 Chapter 21 8>

Chapter 21 8 Naming Amides • For 1 amide, drop -ic or -oic acid from the carboxylic acid name, add -amide. • For 2 and 3 amides, the alkyl groups bonded to nitrogen are named with N￾to indicate their position. CH3 CHC N O CH2 CH3 CH3 CH3 N-ethyl-N,2-dimethylpropanamide N-ethyl-N-methylisobutyramide =>

PhOCH,C- Cyclic Amides COOH acylated. inactive enzyme Reaction of-NH2 and-COOH on same molecule produces a cyclic amide,lactam. To name,add word lactam to the IUPAC acid name or replace the -ic acid of common name with -olactam. 4-aminopentanoic acid lactam N-H y-valerolactam CH; => Chapter 21 9

Chapter 21 9 Cyclic Amides • Reaction of -NH2 and -COOH on same molecule produces a cyclic amide, lactam. • To name, add word lactam to the IUPAC acid name or replace the -ic acid of common name with -olactam. N O CH3 H 4-aminopentanoic acid lactam -valerolactam =>

0 PhOCH,C- NH CH Nitriles CH3 COOH acylated. mnactive .-C=N can be hydrolyzed to carboxylic enzyme acid,so nitriles are acid derivatives. Nitrogen is sp hybridized,lone pair tightly held,so not very basic(pKp about 24) 3> acetonitrile propyne Chapter 21 10

Chapter 21 10 Nitriles • -CN can be hydrolyzed to carboxylic acid, so nitriles are acid derivatives. • Nitrogen is sp hybridized, lone pair tightly held, so not very basic (pKb about 24). =>