Chapter Twelve Introduction to Organic Chemistry: Alkanes James E. Mayhugh Copyright © 2010 Pearson Education, Inc. Fundamentals of General, Organic and Biological Chemistry 6th Edition 1

12.1 The Nature of Organic Molecules ►Organic chemistry: The study of carbon compounds. ►Carbon ALWAYS forms four bonds. 2

►Carbon’s 4 bonds can be any combination of single, double and triple bonds 3

12.4 Drawing Organic Structures Condensed structure: A shorthand way of drawing structures in which C-C and C-H bonds are understood rather than shown. 4

12.4 Drawing Organic Structures Line structure: An even shorter notation: 5

12.2 Families of Organic Molecules: Functional Groups ►Organic compounds are put into families (categories) according to ►The types of atoms attached to the carbons ►The types of bonds between the carbons ►Single, double, triple 6

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Organic Nomenclature ►Basic naming system (nomenclature): 8

Hydrocarbon Nomenclature ►The simplest group of Families are the hydrocarbons… compounds containing only carbon and hydrogen ►All carbon-carbon single bonds: alkanes ►At least one C=C double bond: alkenes ►At least one C  C triple bond: alkynes 9

Hydrocarbon Nomenclature ►Hydrocarbons can be ►“straight” chain 10

Hydrocarbon Nomenclature ►Hydrocarbons can be ►“straight” chain ► branched chain 11

Hydrocarbon Nomenclature ►Hydrocarbons can be ►“straight” chain ► branched chain ► cyclic 12

12.6 Naming Alkanes ►Suffix: -ane ►Parent : based on # of Carbons in longest, continuous chain 13

1 carbonmeth- 2 carbonseth- 3 carbonsprop- 4 carbonsbut- 5 carbonspent- 6 carbonshex- 7 carbonshept- 8 carbonsoct- 9 carbonsnon- 10 carbonsdec- 14

12.6 Naming Alkanes ►Examples of “Straight chain” alkanes: CH 3 CH 2 CH 3 15

►Branched-chain alkanes (Rules are on following slides) 16

►Branched-chain alkanes have “substituents” branching off of the main chain. ►For hydrocarbons, these substituents (or “branches”) are also hydrocarbons ►# of carbons in branch: normal prefix ►Suffix of hydrocarbon branch: -yl ►Name must include WHICH carbon of the main chain the branch is connected to Naming Branched-Chain Alkanes 17

►STEP 1: Name the main chain (parent + suffix). Find the longest continuous chain of carbons! ►STEP 2: Number the carbon atoms in the main chain. Begin at the end nearer the first branch point ►STEP 3: Identify the branching substituents, and number each according to its point of attachment to the main chain ►STEP 4:Write the name as a single word, ►If two or more identical substituents are present, use one of the prefixes di-, tri-, tetra- ►If two or more different substituent groups are present, cite them in alphabetical order 12.6 Naming Branched Alkanes 18

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12.9 Naming Cyclic Alkanes 20

►Naming rules are mostly the same as for other alkanes ►Additional Rules: ►The ring is ALWAYS the main chain ►The prefix “cyclo” is added to the name of the main chain ►If only 1 branch, it doesn’t need to be numbered ►If more than one branch, number the carbons in the ring to get the lowest combination of numbers of branch locations Naming Cyclic Alkanes 21

End of Chapter 12 22

Chapter Seven Chapter Thirteen Alkenes andAlkynes Fundamentals of General, Organic and Biological Chemistry 6th Edition James E. Mayhugh Copyright © 2010 Pearson Education, Inc. 23

13.2 Naming Alkenes and Alkynes (rules on following slides) 24

13.2 Naming Alkenes and Alkynes 25

13.2 Naming Alkenes and Alkynes 26

13.2 Naming Alkenes and Alkynes ►Very similar rules as for alkanes ►Additional rules: ►Choose longest chain that contains the double or triple bond ►Suffix for alkenes: -ene ►Suffix for alkynes: -yne ►Include a number with the parent to indicate which carbon the double/triple bond starts on. 27

►Cyclic alkene special rules ►Carbons 1 and 2 MUST go “through” the double bond ►If there is more than one double bond, number the ring to give the double bonds the lowest numbers… then worry about branches. ►3-methylcylclopentene 28

►5-ethyl-1,3-cylclohexene 29

End of Chapter 13 30

Chapter Seven Chapter Fourteen Some Compounds With Oxygen or a Halogen James E. Mayhugh Copyright © 2010 Pearson Education, Inc. Fundamentals of General, Organic and Biological Chemistry 6th Edition 31

14.1 Alcohols and Ethers ►An alcohol has an –OH covalently bonded to a carbon chain. ►These compounds are NOT basic. ►An ether has an O in the midst of a carbon chain. 32

14.3 Naming Alcohols (rules on following slides) 4-methyl-1-cyclohexanol methanol 1-propanol (only 3 carbons, not 4) 33

14.3 Naming Alcohols ►1. Number the longest carbon chain starting at the end that gets you to the OH the quickest. ►2. Suffix: replace the “e” at the end of the normal name for the main chain with “ol” ►3. Denote location of the OH the same way you show the location of a double or triple bond ►4. Name and slow location of any hydrocarbon branches. 34

14.8 Ethers Ethers are named by identifying the two carbon “branches” attached to the oxygen atom (in alph. order) and adding the word ether. 35

14.8 Ethers Butyl propyl ether 36

14.10 Halogen Containing Compounds 37

14.10 Halogen Containing Compounds ►Halogens: Fluorine, chlorine, bromine, iodine ►As a branch: fluoro, chloro, bromo, iodo ► Halogen branches are given “numbering preference” over hydrocarbon branches ►But NOT over any substituent that determines the family of the compound (like alcohols, double bonds, etc.) 38

End of Chapter 14 39

Chapter Seven Chapter Seventeen Carboxylic Acids Fundamentals of General, Organic and Biological Chemistry 6th Edition James E. Mayhugh Copyright © 2010 Pearson Education, Inc. 40

17.1 Carboxylic Acids ►Carboxylic acids look like a combination of an alcohol and an aldehyde … on the same carbon. 41

17.1 Carboxylic Acids ►Carboxylic acids ►Suffix: -oic acid ►No need to number the acid group… it has to be on an end carbon, so it is automatically “1-” propanoic acid 42

17.1 Carboxylic Acids methanoic acid (common name: formic acid) CH 3 CO 2 H ethanoic acid (common name: acetic acid) 43

17.3 Acidity of Carboxylic Acids Carboxylic acids are weak acids (ethanoic acid) 44

End of Chapter 17 45

Chapter Seven Chapter Sixteen Aldehydes and Ketones James E. Mayhugh Copyright © 2010 Pearson Education, Inc. Fundamentals of General, Organic and Biological Chemistry 6th Edition 46

16.1 The C=O group ►Both aldehydes and ketones contain a C=O group ►They are NOT alkenes… alkenes have C=C bonds ►The difference between aldehydes and ketones is the placement of the C=O group. 47

16.1 Aldehydes ►Aldehydes: ►The Carbon of the C=O group is one of the end carbons ►Suffix: -al ►No need to show its number… it’s ALWAYS “1” if it’s an aldehyde. 48

16.2 Aldehydes Propanal 3-methylbutanal CH 3 CHO Ethanal methanal (common name: formaldehyde) 49

16.1 Ketones ►Ketones: ►The Carbon in the C=O group is one of the INTERIOR carbons ►Suffix: -one ►Location of the =O must be numbered (except for propanone and butanone) 50

16.2 Ketones 2-butanone 4-methyl-3-hexanone CH 3 COCH 2 CH 2 CH 3 (how can you know it’s not an ether??) 2-pentanone cyclohexanone 51

End of Chapter 16 52

It may be hard to believe, but… 53

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