1. ORGANIC CHEMISTRY

2. -Organic molecules contain only C, H, O, N and sometimes S and P
organic substances have been recorded

3. What allows for the diversity of organic compounds?
Carbon can make 4 bonds
The 4 bonds can be a combination of single, double, and triple bonds
methanal, CH2O
methane, CH4
ethanenitrile, CH3CN

4. Naming Hydrocarbons

5. What’s in a Name
Assembled from components that describe various features of the molecule.
root
suffix
Functional group
Number of carbons in the longest chain
Ex:
meth
ane
Ex:
butan ol

6. Root Name = Longest Chain
The longest continuous chain of carbons containing the principal functional group defines the root name. 
Other groups attached to this chain are called substituents.

7. Longest Carbon Chain Name
meth- = 1 carbon
eth- = 2
prop- = 3
but- = 4
pent- = 5
hex- = 6
hept- = 7
oct- = 8
non- = 9
dec- = 10
undec- = 11
dodec- = 12

8. Just FYI… 13 trideca- 30 triaconta- 500 pentacta- 7000 heptalia- 14
tetradeca- 40
tetraconta-
600
hexacta
8000
octalia- 15
pentadeca 50
pentaconta-
700
heptacta-
9000
nonalia- 16
hexadeca- 60
hexaconta-
800
octacta- 17
heptadeca 70
heptaconta-
900
nonacta- 18
octadeca- 80
octaconta-
1000
kilia- 19
nonadeca- 90
nonaconta-
2000
dilia- 20
icosa-
100
hecta-
3000
trilia- 21
heneicosa
200
dicta-
4000
tetralia- 22
docosa
300
tricta-
5000
pentalia- 23
tricosa
400
tetracta-
6000
hexalia-

9. Principal Functional Group = Suffix
The principal functional group is used to define the class the compound belongs to e.g. an alkene, alcohol, etc.
Determines the suffix of molecule’s name
Refer to ‘Families of Organic Compounds’ handout

10. Lesson 3 Success Criteria
Student will be able to:
Recognize the molecular formula of alkanes
Draw different structures of alkanes, cycloalkanes & haloalkanes.
Name alkanes, cycloalkanes & haloalkanes using IUPAC rules
Determine if a compound is a structural isomer

11. Basic Naming Rules
The IUPAC systematic name of an organic compound can be constructed based on a series of steps and rules:
Identification of the principal functional group and substituents
Identification of the longest continuous chain containing the principal functional group.
Assign locants (i.e. numbers) to the principal functional group and substituents.

12. First Set of Functional Groups:
HYDROCARBONS

13. Hydrocarbons:
When an organic molecule is composed only of hydrogen and carbon, it is called a hydrocarbon:
Alkanes: Hydrocarbons with single bonds
Alkenes: Hydrocarbons with double bond(s)
Alkynes: Hydrocarbons with triple bond(s)

14. ALKANES Characterized by C-C single bonds
Also known as saturated hydrocarbons
empirical formula = CnH2n+2
 CnH2n+2, n=8
= C8H18

15. ALKANES
Properties:
Hydrophobic (does not mix with water and other polar substances)
Generally low boiling points (due to weak London Dispersion Forces)
- Longer alkane molecules have higher boiling points

16. ALKANES Some IUPAC* names of alkanes: ethane propane butane
All alkanes have the suffix “ane”
*International Union of Pure and Applied Chemistry

17. ALKANES IUPAC naming system: Molecular
formula Expanded Molecular Formula Name
CH CH methane
C2H CH3CH ethane
C3H CH3CH2CH propane
C4H CH3CH2CH2CH3 butane
C5H CH3CH2CH2CH2CH3 pentane
C6H CH3CH2CH2CH2CH2CH3 hexane
C7H CH3CH2CH2CH2CH2CH2CH3 heptane
C8H CH3CH2CH2CH2CH2CH2CH2CH3 octane
C9H CH3CH2CH2CH2CH2CH2CH2CH2CH3 nonane
C10H CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3 decane

18. ALKANES IUPAC naming system: Name the following alkanes: nonane hexane1 2 3 4 5 6 1 2 3 4 5 6 7 8 9
nonane
hexane

19. Substituents: Branches in Chains
Not all alkanes are straight chains. Some alkanes have alkyl side groups (alkyl substituents) attached.
-CH methyl
-C2H ethyl
-C3H propyl
-C4H butyl
-C5H pentyl
-C6H hexyl
-C7H heptyl
-C8H octyl
Ex:
methyl group
name: 2-methylbutane

20. For alkanes with side groups…
IUPAC naming system:
For alkanes with side groups…
Substituent(s)
prefix
suffix
family
Branches
Number of carbons in the longest chain
Ex:
2-methyl
but
ane

21. Assigning Locants (i.e. numbering)
The numbers that define the positions of the principal functional group and substituents are called locants.
Compounds are numbered from one end of the longest continuous chain.
The locants are assigned such that the principal functional group gets the lowest possible locant

22. Name the following branched alkanes
IUPAC naming system:
Name the following branched alkanes 1 2 3 4 5 1 2 3 4 5
2-methylpentane
3-methylpentane
When there is ambiguity, the substituent must be numbered according to the carbon atom that it is attached to
(aim to get the lowest possible number)

23. First Point of Difference:
Which name is incorrect? 1 2 3 4 5 5 4 3 2 1
2-methylpentane
4-methylpentane
Aim for the lowest possible number when counting.

24. ALKANES
For alkanes with multiple branches of the same kind attached to the main chain….
give each branch a number.
list the numbers in ascending order.
give the branch name a multiplying prefix (i.e. di, tri, tetra, etc.) to indicate the number of identical branches.
put commas between numbers, and hyphens between numbers and letters.
No space!
hept
ane
Ex:
4,6-dimethyl

25. ALKANES CH3 - CH - CH3 | CH3 - CH - CH2 CH3 IUPAC naming system:
Name the following branched alkane 4 5
Find the longest continuous chain of C atoms (parent chain)
CH3 - CH - CH3 |
CH3 - CH - CH2
CH3 1 2 3
Identify any
substitutents
No space!
2,4 -dimethyl
pentane

26. ALKANES IUPAC naming system:
For alkanes with multiple, but different kinds of branched groups…
name the branched groups in alphabetical order.
give the branch name a number to indicate which carbon in the main chain it is bonded with.
put commas between numbers, and hyphens between numbers and letters.
hept
ane
Ex:
4-ethyl-6-methyl

27. CH3 | CH2 - CH2 CH2 - CH - CH2 - CH3 CH - CH3 3-ethyl -2-methyl7
The order of substituents in the name is based on alphabetical order 5 6 3
3-ethyl
-2-methyl
heptane 4
No space! 2 1

28. Numbering (con’t)
If numbering a functional group results in a "tie" then the first point of difference rule. The first time a difference in numbering occurs, then the method that gives the lower number at this first difference is used.
In the event that there is no first point of difference then alphabetisation is used.

29. ALKANES IUPAC naming system: Name the following branched alkane3 4 5 6 2 7
The order of substituents in the name is based on alphabetical order 8 1 9
4,5,5-triethyl
-3,6,6-trimethyl
nonane

30. ALKANES Drawing alkanes:
3 types of diagrams—all showing the same molecule
Structural diagram
Condensed diagram
CH3CH2CH2CH2CH2CH3
Line diagram

31. ALKANES Drawing alkanes: Line diagrams:2 4 6 1 3 5
Every end or point on a line diagram represents a carbon atom. Hydrogen atoms are not shown.

32. ALKANES Drawing alkanes:
Draw the following alkanes using line diagrams
2-methylbutane
3-ethyl-3,4-dimethylheptane 2 4 6 2 4 1 3 5 7 1 3

33. Nomenclature of Alkanes
Write the structure of 3-ethyl-2-methylpentane.

36. No First Point of Difference
In the event that there is no first point of difference then alphabetisation is used to determine numbering.
Name this alkane:
3-ethyl-6-methyloctane 1 2 3 4 5 6 7 8
NOT
6-ethyl-3-methyloctane 1 2 3 4 5 6 7 8
Two branches occur at C-3 and C-6, regardless of how the parent chain is numbered

37. This time, there is a first point of difference at C-41 2 3 4 5 6 7 8
This time, there is a first point of difference at C-4
6-ethyl-3,4-dimethyloctane

38. Condensed Diagrams Bonds are (usually) not drawn. Only atoms are drawn
Entire molecule is written in one line (even branches)
Repeated fragments are simplified with brackets
Branches are also indicated with brackets.

39. Structural diagram
Condensed diagram
CH3CH2CH2CH2CH2CH3
CH3(CH2)4CH3
Condensed diagram

40. CH3 | CH2 - CH2 CH2 - CH - CH2 - CH3 CH - CH37 6 5
BE CAREFUL! A bracket to indicate a branch can be easily confused with a repeated fragment. Typically brackets such as (CH3) indicate a branch, while brackets such as (CH2) indicate a repeated fragment that’s part of a main chain 4 3 2 1 6
CH3CH(CH3)CH(CH2CH3)CH2CH2CH2CH3 1 2 3 4 5 7
CH3CH(CH3)CH(CH2CH3)(CH2)3CH3 6

41. CH3CH2CH(CH3)CH(CH3)CH2CH3
It is common practice to draw the multiple bond in the condensed formula, but
the bond can be omitted when its placement will be obvious
CH3CH2CH2CHCHCH3
CH3CH2CH(OH)CH2CH3
(CH3O)2CH(CH2)4Br

42. CYCLOALKANES

43. Ring-like structures of alkanes
empirical formula = CnH2n
 CnH2n, n=6
= C6H12

44. CYCLOALKANES IUPAC naming system: Name the following alkanes:
cyclobutane
cyclooctane
cyclopentane
The prefix “cyclo” is added to the alkane name

45. Name the following alkanes:
IUPAC naming system:
Name the following alkanes: CH
CH2
CH3CH2CH2
methylcyclohexane
propylcyclobutane
Numbering the lcoation is not required, since the number is implied

46. 3 3 1 1 1 1 3 3
1,3-dimethylcyclohexane
1-ethyl-3-methylcyclohexane
1,3-dimethylcyclohexane
If there are several substituents, the numbering of ring carbons then continues in a direction (clockwise or counter-clockwise) that affords the second substituent the lower possible location number
If two different substituents are present on the ring, they are listed in alphabetical order, and the first cited substituent is assigned to carbon #1.

47. 4-ethyl-1,1,2-trimethylcyclohexane3 1 4 6 5
The disubstituted carbon becomes #1 because the total locator numbers are thereby kept to a minimum. The methyl substituent is then located on carbon #2 (clockwise numbering), and the ethyl group is located on #4
4-ethyl-1,1,2-trimethylcyclohexane

48. CYCLOALKANES IUPAC naming system:
Draw the following alkanes using line structures:
1,1-dipropylcyclopropane
1-ethyl-1,2,5-trimethylcyclopentane

49. HALOALKANES

50. HALOALKANES
Alkanes with halogen atoms
Also known as alkyl halides

51. HALOALKANES IUPAC naming system: Halogen groups: -F fluoro -Cl chloro
-Br bromo
-I iodo
Just like alkyl substituents, the halogens are placed at the beginning of the name, and are ordered alphabetically.

52. HALOALKANES IUPAC naming system: Name the following haloalkanes:
1,2-dibromo-1-chlorobutane
2-bromo-2-methylpropane
2-bromo-2-chloro-1,1,1-trifluoroethane

53. STRUCTURAL ISOMERS

54. STRUCTURAL ISOMERS
Compounds with the same molecular formula but with different bonding arrangements are structural isomers.
Butane isomers
Pentane isomers

55. STRUCTURAL ISOMERS Ex: Structural isomers of hexane + boiling points
Changing the structure affects the boiling point
This structure can easily stack and form more London Dispersion Forces with neighbouring hexane molecules

56. STRUCTURAL ISOMERS
Draw all of the structural isomers of heptane using line structures:

57. STRUCTURAL ISOMERS
The longer the chain, the greater the number of structural isomers
Number of Carbon Atoms 4 5 6 7 8 9 10 12 15
Number of Isomers 2 3 5 9 18 35 75
355
4347