RuCt&0号 Organic Chemistry,6th Edition R L.G.Wade,Jr. Chapter 18 Ketones and Aldehydes Jo Blackburn Richland College,Dallas,TX Dallas County Community College District ©2006，Prentice Hall
Chapter 18 Ketones and Aldehydes Jo Blackburn Richland College, Dallas, TX Dallas County Community College District © 2006, Prentice Hall Organic Chemistry, 6th Edition L. G. Wade, Jr
RC-0 Carbonyl Compounds R TABLE 18-1 Some Common Classes of Carbonyl Compounds Class General Formula Class General Formula ketones R-C-R aldehydes carboxylic acids R-C-OH acid chlorides 0 esters R-C-O-R amides Copyright 2005 Pearson Prentice Hall,Inc. => Chapter 18
Chapter 18 2 Carbonyl Compounds =>
Carbonyl Structure R Carbon is sp2 hybridized. C=O bond is shorter,stronger,and more polar than C=C bond in alkenes. length energy ketone C=O bond 1.23A 745 kJ/mol (178 kcal/mol alkene C=C bond 1.34A 611 kJ/mol (146 kcal/mol) Copyright2005 Pearson Prentice Hall,Inc. Chapter 18 3
Chapter 18 3 Carbonyl Structure • Carbon is sp2 hybridized. • C=O bond is shorter, stronger, and more polar than C=C bond in alkenes. =>
RC-0 IUPAC Names R for Ketones Replace -e with -one.Indicate the position of the carbonyl with a number. Number the chain so that carbonyl carbon has the lowest number. For cyclic ketones the carbonyl carbon is assigned the number 1. Chapter 18
Chapter 18 4 IUPAC Names for Ketones • Replace -e with -one. Indicate the position of the carbonyl with a number. • Number the chain so that carbonyl carbon has the lowest number. • For cyclic ketones the carbonyl carbon is assigned the number 1. =>
RC-0 R Examples CH-CH CH3 3-methyl-2-butanone Br 3-methylbutan-2-one 3-bromocyclohexanone 0 cus-E-CH-cton CH3 4-hydroxy-3-methyl-2-butanone 4-hydroxy-3-methylbutan-2-one 三> Chapter 18 6
Chapter 18 5 Examples CH3 C O CH CH3 CH3 O Br CH3 C O CH CH3 CH2OH 3-methyl-2-butanone 3-methylbutan-2-one 3-bromocyclohexanone 4-hydroxy-3-methyl-2-butanone 4-hydroxy-3-methylbutan-2-one =>
RC-0 R Naming Aldehydes IUPAC:Replace -e with -al. The aldehyde carbon is number 1. If-CHO is attached to a ring,use the suffix -carbaldehyde. => Chapter 18 6
Chapter 18 6 Naming Aldehydes • IUPAC: Replace -e with -al. • The aldehyde carbon is number 1. • If -CHO is attached to a ring, use the suffix -carbaldehyde. =>
R- Examples CH3 3-methylpentanal CHO 2-cyclopentenecarbaldehyde cyclopent-2-en-1-carbaldehyde => Chapter 18 7
Chapter 18 7 Examples CH3 CH2 CH CH3 CH2 C H O CHO 3-methylpentanal 2-cyclopentenecarbaldehyde cyclopent-2-en-1-carbaldehyde =>
RC+-0 Name as Substituent R On a molecule with a higher priority functional group,C=O is oxo-and -CHO is formyl. Aldehyde priority is higher than ketone. COOH CHO 3-methyl-4-oxopentanal 3-formylbenzoic acid => Chapter 18 8
Chapter 18 8 Name as Substituent • On a molecule with a higher priority functional group, C=O is oxo- and -CHO is formyl. • Aldehyde priority is higher than ketone. CH3 C CH CH3 CH2 C H O O COOH CHO 3-methyl-4-oxopentanal 3-formylbenzoic acid =>
Common Names R for Ketones Named as alkyl attachments to -C=O. Use Greek letters instead of numbers. 0 em t cu-cu CHCH-C-CH-CHs CH3 Br CH3 methyl isopropyl ketone a-bromoethyl isopropyl ketone Chapter 18 9
Chapter 18 9 Common Names for Ketones • Named as alkyl attachments to -C=O. • Use Greek letters instead of numbers. CH3 C O CH CH3 CH3 CH3CH C O CH CH3 CH3 Br methyl isopropyl ketone a-bromoethyl isopropyl ketone =>
Historical Common RC-0 Names 0 >CH; acetone acetophenone benzophenone => Chapter 18 10
Chapter 18 10 Historical Common Names CH3 C O CH3 C CH3 O C O acetone acetophenone benzophenone =>