1. Introduction
Most of the advances in the pharmaceutical industry are based on a knowledge of organic chemistry.
Many drugs are organic compounds
Life as we know it is based on organic chemistry.
Most biologically important compounds contain carbon:
DNA, RNA
proteins
carbohydrates

2. Introduction Some familiar organic compounds: Acetic acid “ether”
aspirin
Ethyl alcohol

3. Introduction
Organic compounds that are soluble in polar solvents such as water generally have a polar functional group present in the molecule.
An atom or group of atoms that influences the way the molecule functions, reacts or behaves.
an atom or group of atoms in a molecule that undergoes predictable chemical reactions
the center of reactivity in an organic molecule

4. Introduction
Functional groups that contain O or N atoms often lead to a polar organic molecule

6. Functional Groups
Example: Name the functional groups that are present in the following compounds:
CH3CH2OH O
H2C = CHCOH
CH3CH2NCH3
CH3

7. Functional Groups
Example: Name the functional group(s) that is (are) present in the following compounds:
H2C CH2
CH3NHCH2CH2OCH3 O

8. Hydrocarbons The simplest organic compounds are the hydrocarbons:
organic compounds that contain only carbon and hydrogen
four general types:
alkanes
alkenes
alkynes
aromatic hydrocarbons

9. Hydrocarbons Alkanes: hydrocarbons that contain only single bonds
Examples:
Methane CH4
ethane H H
H – C – C – H
H H

10. Alkanes Organic compounds can be represented in many different ways:
molecular formula: C4H10 (butane)
Lewis structure:
Condensed structural formula
CH3CH2CH2CH3
Line angle drawings

11. Alkanes
Some of the simplest alkanes:
You must know these!!!

12. Alkanes
Some of the simplest alkanes:
You must know these!!!

13. Fig For a series of alkanes or cycloalkanes, melting point increases as carbon chain length increases.

14. Saturated Hydrocarbons cont’d
Fig. 12.3
Molecular structures of (a) methane, (b) ethane, and (c) propane, the three simplest alkanes.

15. Alkanes
The previous alkanes are also called straight-chain hydrocarbons:
all of the carbon atoms are joined in a continuous chain
Alkanes containing 4 or more carbons can also form branched-chain hydrocarbons (branched hydrocarbons)
some of the carbon atoms form a “branch” or side-chain off of the main chain

16. Alkanes An example of a straight chain hydrocarbon:
C5H12 CH3CH2CH2CH2CH3 pentane
Examples of a branched hydrocarbon:
C5H12 CH3CHCH2CH3 CH3
CH3 CH3CCH3
CH3
2-methylbutane
2,2-dimethylpropane

17. Alkanes
The three structures shown previously for C5H12 are structural isomers:
compounds with the same molecular formula but different bonding arrangements
Structural isomers generally have different properties:
different melting points
different boiling points
often different chemical reactivity

18. Alkanes
Alkanes with three or more carbons can also form rings or cycles.
Cycloalkanes:
Alkanes containing a ring structure that is held together by C – C single bonds
Examples:
CH2
H2C
CH2
cyclopropane

19. Alkanes Examples of cycloalkanes: CH2 H2C CH2 cyclopentane H2C CH2 H2C
cyclohexane

20. Naming Alkanes Alkane Nomenclature:
Find the longest continuous chain of carbon atoms and use the name of the chain for the base name of the compound:
longest chain may not always be written in a straight line 1 2
CH3 - CH - CH3
CH2 - CH2 - CH2 - CH3
Base name:
hexane 3 4 5 6

21. Alkanes Alkane Nomenclature:
Number the carbon atoms in the longest chain beginning with the end of the chain closest to a substituent
groups attached to the main chain that have taken the place of a hydrogen atom on the main chain 1
A substituent 2
CH3 - CH - CH3
CH2 - CH2 - CH2 - CH3 3 4 5 6

22. Alkanes Alkane Nomenclature:
Name and give the location of each substituent group
A substituent group that is formed by removing an H atom from an alkane is called an alkyl group:
Name alkyl groups by dropping the “ane” ending of the parent alkane and adding “yl”

23. Alkanes Alkane Nomenclature: Common alkyl groups (substituents):
CH3 methyl
CH3CH2 ethyl
CH3CH2CH2 propyl
CH3CH2CH2CH2 butyl
Know these! 1 2
CH3 - CH - CH3
CH2 - CH2 - CH2 - CH3
2-methylhexane 3 4 5 6

24. Alkanes Alkane Nomenclature:
Halogen atoms are another common class of substituents.
Name halogen substituents as “halo”:
Cl chloro
Br bromo
I iodo

25. Alkanes Alkane Nomenclature:
When two or more substituents are present, list them in alphabetical order:
Butyl vs. ethyl vs. methyl vs. propyl
When more than one of the same substituent is present (i.e. two methyl groups), use prefixes to indicate the number:
Di = two
Tri = three
Tetra = four
Penta = five
Know these.

26. Alkanes Example: Name the following compounds: CH3CH2CHCH2CH3 CH3

27. Alkanes Example: Name the following compounds: CH3CH2CHCH3 CH2CH2BrCl

28. Alkanes
You must also be able to write the structure of an alkane when given the IUPAC name.
To do so:
Identify the main chain and draw the carbons in it
Identify the substituents (type and #) and attach them to the appropriate carbon atoms on the main chain.
Add hydrogen atoms to the carbons to make a total of 4 bonds to each carbon

29. Alkanes
Example: Write the condensed structure for the following compounds:
3, 3-dimethylpentane
3-ethyl-2-methylhexane
2-methyl-4-propyloctane
1, 2-dichloro-3-methylheptane

30. Hydrocarbons Alkanes are often called saturated hydrocarbons
they contain the largest possible number of hydrogen atoms per carbon atom.
Alkenes, alkynes, and aromatic hydrocarbons are called unsaturated hydrocarbons
they contain less hydrogen than an alkane having the same number of carbon atoms

31. Hydrocarbons Alkenes: hydrocarbons that contain a C = C double bond
H2C = CH2 (ethene)
Alkynes:
hydrocarbons that contain a C C triple bond
H – C C – H (ethyne)

32. Alkenes
Alkenes:
unsaturated hydrocarbons that contain a C=C double bond
Alkene Nomenclature:
Names of alkenes are based on the longest continuous chain of carbon atoms that contains the double bond.

33. Alkenes Alkene Nomenclature
Find the longest continuous carbon chain containing the double bond.
Change the “ane” ending from the corresponding alkane to “ene”
butane butene
propane propene
octane octene

34. Alkenes Alkene Nomenclature
Indicate the location of the double bond using a prefix number
designate the carbon atom that is part of the double bond AND nearest to the end of the chain
Name all other substituents in a manner similar to the alkanes.
Use a prefix to indicate the geometric isomer present, if necessary.

35. Alkenes Alkene Nomenclature
Different geometric isomers are possible for many alkenes.
Compounds that have the same molecular formula and the same groups bonded to each other, but different spatial arrangements of the groups
cis isomer
trans isomer

36. Alkenes Alkene Nomenclature Cis isomer:
two identical groups (on adjacent carbons) on the same side of the C = C double bond
Trans isomer:
two identical groups (on adjacent carbons) on opposite sides of the C = C double bond

37. Alkene CH3 CH3 CH3 H C = C C = C H H H CH3 cis-but-2-ene
trans-but-2-ene

38. Alkene For an alkene with the general formula A P C = C B Q
cis and trans isomers are possible only if
A = B and
P = Q

39. Alkene Example: Name the following alkenes: CH3CH2 H C = C H H
CH3CHCH2 CH2CH3
CH3

40. Alkenes Example: Draw the structures for the following compounds:
2-chloro-3-methyl-but-2-ene
trans-3, 4-dimethyl-pent-2-ene
cis-6-methyl-hept-3-ene

41. Alkynes Alkynes: unsaturated hydrocarbons that contain a
C C triple bond
Alkyne Nomenclature:
Identify the longest continuous chain containing the triple bond
To find the base name, change the ending of the corresponding alkane from “ane” to “yne”

42. Alkynes Alkyne Nomenclature:
Use a number to designate the position of the triple bond
number from the end of the chain closest to the triple bond
just like with alkenes
Name substituents like you do with alkanes and alkenes

43. Alkynes Example: Name the following compounds: CH3CH2C CCHCH3 CH2CH3
CH2CH2C CH Cl

44. Alkynes Example: Draw the following alkynes. 4-chloro-pent-2-yne
3-propyl-hex-1-yne

45. Hydrocarbons Aromatic hydrocarbons:
contain a planar ring structure in which the carbon atoms are connected by delocalized electrons H C
H - C
C - H
benzene
H - C
C - H C H

46. Aromatic Compounds
Aromatic compounds contain benzene ring.
Benzene has:
6 C atoms and 6 H atoms.
Two possible Lewis structures.
C6H6

47. Naming of Aromatic Compounds
Aromatic compounds are named:
With benzene as the parent chain. (note if this structure is a substituent, we use the name phenyl)
Name of substituent comes in front of the “benzene”.
methylbenzene chlorobenzene ethylbenzene
CH3 Cl
CH2-CH3

48. Naming of Aromatic Compounds
When two groups are attached to benzene, the ring is numbered to give
the lower numbers to the substituents.
Start numbering from a special name (if we have).
If we do not have, number them to get the smallest set of numbers.
List them by alphabetical order.
Ortho
Meta
Para