Organic Chemistry,6th Edition L.G.Wade,Jr. Chapter 20 Carboxylic Acids Jo Blackburn Richland College,Dallas,TX Dallas County Community College District ©2006，Prentice Hall
Chapter 20 Carboxylic Acids Jo Blackburn Richland College, Dallas, TX Dallas County Community College District © 2006, Prentice Hall Organic Chemistry, 6th Edition L. G. Wade, Jr
Introduction Carbonyl (-C=O)and hydroxyl (-OH)on the same carbon is carboxyl group. Carboxyl group is usually written-COOH. Aliphatic acids have an alkyl group bonded to -COOH. Aromatic acids have an aryl group. Fatty acids are long-chain aliphatic acids. R-C-0-H+H,0:→ +H,O+ pK,=5 (K≡105) acid => 2 carboxylate
Chapter 20 2 Introduction • Carbonyl (-C=O) and hydroxyl (-OH) on the same carbon is carboxyl group. • Carboxyl group is usually written -COOH. • Aliphatic acids have an alkyl group bonded to -COOH. • Aromatic acids have an aryl group. • Fatty acids are long-chain aliphatic acids. =>
Common Names Many aliphatic acids have historical names. Positions of substituents on the chain are labeled with Greek letters. 0 -C-C-C-C-C-C-0H NH, CH3-CH一C一OH CH2一CH2-CH2-C一OH a-chloropropionic acid y-aminobutyric acid => Chapter 20 3
Chapter 20 3 Common Names • Many aliphatic acids have historical names. • Positions of substituents on the chain are labeled with Greek letters. =>
IUPAC Names Remove-e from alkane (or alkene) name,add -oic acid. The carbon of the carboxyl group is #1. CIO H CHCH-CHC-OH CC、 H COOH 2-chlorobutanoic acid trans-3-phenyl-2-propenoic acid (cinnamic acid) => Chapter 20 4
Chapter 20 4 IUPAC Names • Remove -e from alkane (or alkene) name, add -oic acid. • The carbon of the carboxyl group is #1. CH3 CH2 CHC Cl OH O 2-chlorobutanoic acid Ph C H C H COOH trans-3-phenyl-2-propenoic acid (cinnamic acid) =>
Naming Cyclic Acids Cycloalkanes bonded to -COOH are named as cycloalkanecarboxylic acids. Aromatic acids are named as benzoic acids. COOH COOH CH(CH3)2 OH 2-isopropylcyclopentanecarboxylic acid -hydroxybenzoic acid (salicylic acid) => Chapter 20 5
Chapter 20 5 Naming Cyclic Acids • Cycloalkanes bonded to -COOH are named as cycloalkanecarboxylic acids. • Aromatic acids are named as benzoic acids. COOH CH(CH3 ) 2 2-isopropylcyclopentanecarboxylic acid COOH OH o-hydroxybenzoic acid (salicylic acid) =>