Organic Chemistry,6th Edition L.G.Wade,Jr. Chapter 9 Alkynes Jo Blackburn Richland College,Dallas,TX Dallas County Community College District ©2006，Prentice Hall
Chapter 9 Alkynes Jo Blackburn Richland College, Dallas, TX Dallas County Community College District © 2006, Prentice Hall Organic Chemistry, 6th Edition L. G. Wade, Jr
Introduction Alkynes contain a triple bond. General formula is C,H2n-2. Two elements of unsaturation for each triple bond. Some reactions are like alkenes: addition and oxidation. Some reactions are specific to alkynes. > Chapter 9 2
Chapter 9 2 Introduction • Alkynes contain a triple bond. • General formula is CnH2n-2 . • Two elements of unsaturation for each triple bond. • Some reactions are like alkenes: addition and oxidation. • Some reactions are specific to alkynes. =>
Nomenclature:IUPAC Find the longest chain containing the triple bond. Change -ane ending to -yne. Number the chain,starting at the end closest to the triple bond. Give branches or other substituents a number to locate their position. 二> Chapter 9 3
Chapter 9 3 Nomenclature: IUPAC • Find the longest chain containing the triple bond. • Change -ane ending to -yne. • Number the chain, starting at the end closest to the triple bond. • Give branches or other substituents a number to locate their position. =>
Name these: CH3一C≡CH propyne CH一C≡C-CH2一CH一Br 5-bromo-2-pentyne 5-bromopent-2-yne CHs CH3 CH一CH-CH2一C≡C-CH-CH 2,6-dimethyl-3-heptyne 2,6-dimethylpept-3-yne > Chapter 9 4
Chapter 9 4 Name these: CH3 CH CH3 CH2 C C CH CH3 CH3 CH3 C C CH2 CH2 Br CH3 C CH propyne 5-bromo-2-pentyne 5-bromopent-2-yne => 2,6-dimethyl-3-heptyne 2,6-dimethylpept-3-yne
Additional Functional Groups All other functional groups,except ethers and halides have a higher priority than alkynes. For a complete list of naming priorities, look inside the back cover of your text. => Chapter 9 5
Chapter 9 5 Additional Functional Groups • All other functional groups, except ethers and halides have a higher priority than alkynes. • For a complete list of naming priorities, look inside the back cover of your text. =>