1. Chapter 17: Organic Chemistry
Figures: Basic Chemistry 3rd Ed., Timberlake and Timberlake

2. Organic Chemistry
Organic Chemistry is the chemistry of carbon containing molecules
Originally thought to be produced only by living things… organic
Chemistry is the study of the composition, structure and reactions of matter
The Structure of molecules is very important in organic and biochemistry

3. IUPAC Names: Organic Molecule Prefixes
The names of organic compounds are determined by the IUPAC rules (International Union of Pure and Applied Chemistry). The stem of the name states the number of carbon atoms in the carbon chain of the compounds. The suffix, in this case –ane, indicates the alkane family.

4. Structural Formulas Revisited
Alkanes are written as structural formulas:
Revisit Chapter 6 for more details
Expanded Structure shows each bond
Condensed Structures show each carbon atom and the attached hydrogen atoms
In methane, CH4 the four valence electrons of carbon are shared with the single electrons of four hydrogen (H) atoms. Each pair of electrons is a single bond, which can be drawn as a line. When a structure is drawn to show each bond, it is called a complete structural formula.

5. Drawing Structural (Line) Formulas
Carbon atoms in a chain:
maintain their tetrahedral shape
are connected in a zigzag pattern
are drawn as two dimensional
can be written in many ways
have free rotation in straight chain

6. Conformers
Remember, organic compounds have free rotation around sp3 carbon atoms, this leads to a variety of spatial orientations for the same structure
Conformers: different orientations of the same molecule:

7. Conformers
Let’s consider different conformers of pentane, C5H12:

8. Isomers
Isomers:
Compounds with the same molecular formula but different atomic arrangements
For Example:
Butane (C4H10) has a straight chain and a branched chain form

9. Isomers
Let’s consider different isomers of pentane, C5H12:

10. Alkanes with Substituents
In the IUPAC system:
a carbon branch is named an alkyl-group
halogen atoms are named as halo-group

11. Naming Alkanes Find longest alkane chain Name and number substituents
Substituents are numbers to give the lowest number possible
Substituents are named in alphabetical order, ignore prefixes di-, tri-, etc…

12. Naming Alkanes

13. Learning Check Provide the IUPAC name for the following: Cl CH3 | |
| |
CH3─CH2─CH─CH2─C─CH2─CH3 | Cl

14. Drawing Alkanes from Names
2,2,3-trimethylpentane 2,4-dibromo-3-ethylhexane

15. Take Home Draw the condensed and line structure for
2-bromo-4-chlorobutane.

16. Classifying Carbon Atoms
Primary (1°): attached to one other carbon Secondary (2°): attached to two other carbons Tertiary (3°): attached to three other carbons Quaternary (4°): attached to four other carbons

17. Cycloalkanes Saturated compounds with a ring structure
Have a loss of free rotation
Formed by removal of a H atom form each end carbon
Butane, C4H10
Cyclobutane, C4H8

18. Cycloalkanes
Saturated compounds with a ring structure that have a loss of free rotation
Practice drawing cyclohexane, C6H12

19. Unsaturated Hydrocarbons
Alkenes contain a carbon-carbon double bond (C = C)
Have a fixed structure around the C=C
Named for the longest carbon chain which includes the base alkene
Alkynes contain a carbon-carbon triple bond (C ≡ C)
Named for the longest carbon chain which includes the base alkyne

20. Alkenes and Alkynes

21. cis and trans Isomers of Alkenes
Alkenes have two different isomers that are determined by what groups lie on each side of the double bond:
cis: substituent groups are on the same side of the double bond
trans: substituent groups are on the opposite side of the double bond
MUST have two different groups on C

22. cis and trans Isomers

23. Alkynes
NO rotation around the C≡C and have a straight line structure at the triple bond:
EXAMPLE:

24. Reactions of Alkenes Addition Reactions (Combination Reactions):
Reactants add across the double bond
H2 (hydrogenation) and halogens (F2, Br2, Cl2)
+ 3 H2

25. Reactions of Alkenes Addition Reactions (combination reactions)
HF, HCl, HBr, HI
H2O, creates an alcohol
+ HCl
+ H2O

26. Polymerization of Alkenes
Polymerization is an Addition Reaction:
Addition reaction where one alkene combines with another alkene
Polymer: A molecule with a high molar mass made up of thousands of repeating units.
Monomer: individual molecules used to produce the polymer.

27. Synthetic Polymers in Everyday Items

28. Polymerization
In polymerization, small repeating units called monomers join to form a long-chain polymer

29. Learning Check
What is the structure of polypropylene?

30. Take Home
What is the structure of polystyrene (polyphenylethene)?

31. Recycling Plastics
Recycling is simplified by using codes found on plastic items:

32. Reactions of Alkynes
Alkynes react very similarly to alkenes but often can add two moles of reactant per mole of alkyne (due to triple bond)

33. Aromatic Compounds Benzene (C6H6):
has six electrons shared equally among six carbon atoms in a ring
is written as two possible ring structures
is also represented as a hexagon with a circle drawn inside (common line structure shorthand)

34. Common Aromatic Compounds in Nature and Health

35. Learning Check Select the correct name for the following structure:
1) chlorohexane
2) chlorobenzene
3) 1-chlorobenzene

36. Learning Check
Write the IUPAC name of the following compound:

37. Take Home
Draw the condensed structural formula for 1-bromo-3,4-dichlorobenzene.

38. Alcohols and Ethers
An alcohol contains the hydroxyl (-OH) functional group
In an ether, an oxygen atom is bonded to two carbon atoms

39. Aldehydes and Ketones Contain a carbonyl group (C=O)
In an aldehyde, the carbonyl group is attached to another carbon atom and one hydrogen atom
In a ketone, the carbonyl group attached to two other carbon atoms

40. Oxidation Reactions In organic chemistry (and biochemistry):
Oxidation Reactions typically involve the addition of bonds to oxygen
Reduction Reactions typically involves a gain of hydrogen

41. Classification of Alcohols
Alcohols are:
classified by the number of carbon groups attached to the carbon atom bound to the -OH group:
Primary Alcohol when one carbon group attached
Secondary Alcohols when two carbon groups are attached
Tertiary Alcohols when three carbon groups are attached

42. Classification of Alcohols
Alcohols are:
classified by the number of carbon groups attached to the carbon atom bound to the -OH group:

43. Learning Check Classify the following as 1°, 2°, or 3° alcohols: OH │
CH3─CH2─CH2─OH B. CH3─CH─CH2─CH3
C OH
CH3─C─CH2─CH3
CH3

44. Oxidation of 1 Alcohols form Aldehydes
In the oxidation [O] of a primary alcohol (1):
one H is removed from the –OH group
another H is removed from the C bonded to the –OH
primary alcohol aldehyde
OH O
│ ║
CH3─C─H CH3─C─H + HOH │ H
Ethanol Ethanal
(ethyl alcohol) (acetaldehyde)

45. Oxidation of 2 Alcohols
The oxidation of 2 alcohols is similar, but a ketone is formed:
secondary alcohol ketone
OH O
│ ║
CH3─C─CH CH3─C─CH HOH │ H
2-propanol
(isopropanol)
2-propanone
(acetone)

46. Oxidation of 3 Alcohols
Tertiary (3) alcohols do not readily oxidize:
Tertiary alcohol OH │
CH3─C─CH no product
CH3
NO H on the C─OH to oxidize
2-Methyl-2-propanol

47. Oxidation of Ethanol in the Body
Enzymes (proteins) in the liver oxidize ethanol
the aldehyde product impairs coordination
blood alcohol over 0.4% can be fatal
O O
║ ║
CH3CH2OH CH3CH CH3COH CO2 + H2O
Ethanol Acetaldehyde Acetic acid

48. Percent Blood Alcohol Concentration
A breathalyzer test is used to determine blood level of ethanol

49. Carboxylic Acids and Esters
Both contain a carboxyl group, a carbonyl group attached to a hydroxyl group
A carboxylic acid contains a terminal carboxyl group
An ester contains the carboxyl group between carbon atoms
The H on the hydroxyl is replaced by the C-C bond

50. Amines and Amides Contain a nitrogen atom or nitrogen containing group
In an amine, the functional group is a nitrogen atom
In amides, the hydroxyl group of a carboxylic acid is replaced by a nitrogen group