1. REACTIONS OF ORGANIC COMPOUNDS

2. MAIN TYPES OF REACTIONS in Organic Chem
Addition
Substitution
Elimination
Oxidation
Reduction
Condensation
Hydrolysis
Combustion
Types of Substitution Reactions

3. 1) ADDITION REACTION Atoms added to a double or triple bond
Alkene or Alkyne undergoes addition reaction to break a double or triple bond
Example:
Reactant XY added to alkene makes alkane
To recognize: Two reactants make 1 product

4. 1) ADDITION REACTIONS
Common atoms that can be added to an alkene or alkyne
H and OH (from H2O )
H and X (from H-X) where X= Cl , Br, or I
X and X from (X2) where X= Cl , Br, or I
H and H (from H2)

5. EXAMPLES: Addition Reactions1) 2)

6. ADDITION REACTIONS: ALKENES
Symmetrical molecule reacts with asymmetrical molecule to give one product.
Symmetrical
Asymmetrical

7. Which product is favoured ?
RULES FOR ADDITION
Two asymmetrical molecules react to give two products.
Example:
Which product is favoured ? + or
Asymmetrical
Asymmetrical

8. “MARKOVNIKOV’S” Rule "the rich get richer"
The carbon atom with the largest number of carbon atoms gets the X (halogen) or OH bind to it
Therefore 2- bromobutane is favoured
2-bromobutane
Major product +
Minor Product
1-bromobutane

9. ADDITION REACTIONS: ALKYNES
Also follow Markovnikov’s rule when asymmetrical
1,1,2,2-tetrabromopropane
Asymmetrical

10. ADDITION REACTIONS: ALKYNES
May occur as two addition reactions: + +

11. Addition
Takes place with unsaturated compounds which are usually more reactive that saturated compounds
Takes place with both Double and Triple bonds
Two atoms are added across the electron rich bond
What can be added? X2 H2
H2O HX

12. Addition Addition of halogen
Normally occurs dissolved in a solvent such as CCl4
Alkenes form dihaloalkanes
Alkynes produce dihaloalkenes or tetrahaloalkanes
1,2-dichloroethane

13. Addition Addition of Hydrogen Known as Hydrogenation
Catalysts normally used such at Pt, Pd or Ni
Known as Hydrogenation
Alkene becomes an alkane
Alkyne becomes and alkene or alkane
H2C=CH H 
Heat, catalyst
H H
H-C-C-H

15. Addition Addition of Hydrogen Halides (HX) HX = HCl, HBr, HI (Not HF)
Alkene becomes an alkyl Halide
Alkynes form Monohalo alkenes or dihaloalkanes with
the halogens on the same carbon
H2C=CH HX 
H H
H-C-C-H
H X
HC=CH + HX 
H-C-C-H
H X
+ HX 

16. 2) SUBSTITUTION REACTION
A hydrogen atom or functional group is replaced by a different functional group
To recognize: two compounds react to form two products.
2-bromobutane
butan-2-amine

17. Substitution Reactions
Any reaction in which one atom is replaced by another
Used to place a halogen onto an alkane
The products always are a halocarbon and the acid of the halogen (ex: hydrobromic acid)
Needs ultraviolet light to initiate the reaction
Provides the high energy needed to form the excited state

18. Substitution Rxns What is the products formed in the following rxn?
CH3CH3 + Br2 
sunlight
CH3 CH2Br + HBr
(Why sunlight?)

19. SUBSTITUTION REACTION Aromatics
Aromatics can only undergo substitution reactions

20. 3) ELIMINATION REACTION
atoms are removed form a molecule to form double bonds.
Reverse of addition
To recognize: One reactant breaks into two products

21. ELIMINATION REACTION: Alcohol
undergo elimination dehydration when heated in presence of strong acids, for example: H2SO4
Example:

22. ELIMINATION REACTION: Alkyl Halides
Undergo elimination to produce alkenes
Bromoethane ethene hydrobromic acid

23. Elimination Rxns
Any reaction in which atoms are eliminated from another molecule
This can be done by
Elimination of H2
Elimination of HX
Elimination of H20

24. Elimination Reactions
Loss of H2
- This process is often referred to as Dehydrogenation
H H
H-C-C-H  H2C=CH H2
Heat, catalyst
This type of rxn takes place in industry in what
is know as a catalytic cracking unit

25. Elimination Rxns
Loss of HX
Alkyl halides can also undergo elimination. This is as
known as dehydrohalogenation
H H
H-C-C-H  H2C=CH HX
H X
Base (ex KOH)
The base extract a proton (H+) and X- leaves

26. Elimination Rxns
Loss of H2O
Alcohols can undergo elimination via the loss of water.
This is known as dehydration
H H
H-C-C-H  H2C=CH H2O
H OH
Acid, heat
a) The acid protonates the –OH group, water leaves
Positive carbon remains behind
b) An adjacent proton (H+) leaves next leaving the
electron pair to form the double bond

27. 4) OXIDATION & 5) REDUCTION REACTIONS
Change in the number of H or O atoms bonded to C
Always occur together
One reactant is oxidized while the other is reduced
For now, lets focus on reactant only…

28. 4) OXIDATION
Carbon atom forces more bonds to Oxygen or less to Hydrogen
For example: formation of C=O bond
Occurs in presence of oxidizing agents [O] such as KMnO4, K2Cr2O7, and O3
For now, focus on organic reactant only

29. 4) OXIDATION: Alcohol Alcohol oxidation can form an aldehyde or ketone
Primary Alcohol
Secondary Alcohol
Tertiary Alcohols do not oxidize

30. 4) OXIDATION: Aldehyde
Aldehydes undergo oxidation to produce carboxylic acid
Example:

31. IV- Oxidation/Reduction
Oxidation: the loss of electrons
alternatively, the loss of H, the gain of O, or both
Reduction: the gain of electrons
alternatively, the gain of H, the loss of O, or both

32. 5) REDUCTION REACTION
Carbon atom forms fewer bonds to Oxygen or more bonds to Hydrogen
Aldehydes, ketones and carboxyliic acids can be “reduced” to alcohols
Alkenes and alkynes can be reduced to become alkanes
Occurs in the presence of reducing agents such as LiAlH4, and H2 where Hydrogen [H] is added

33. 5) REDUCTION: Alkene

34. 5) REDUCTION: Aldehyde/Ketone

35. 6) CONDENSATION Water is usually produced in this reaction
two molecules combine to form a single, bigger molecule.
Water is usually produced in this reaction
A carboxylic acid and alcohol can condense to form an ester
called “ esterification”
A carboxylic acid and amine can condense to form an amide

36. Esterification Alcohol + Organic Acid = Water + Ester
Used to make perfumes, scents and flavors
Combination reaction which involves dehydration.
The alcohol becomes the alkyl group and the acid becomes -oate
Methyl propanoate

37. Aspirin – Made by EsterificationHO
C=O OH +
H-O-C-CH3 O 
Acetic acid
Salicylic Acid HO
C=O
O-C-CH3 O
(An alcohol and acid)
Acetyl Salicylic Acid
(Common Name)
“Aspirin”

38. LecturePLUS Timberlake
Ethers
Contain an -O- between two carbon groups
Formed by a condensation reaction of 2 alcohols to remove a molecule of water
Methanol reacts with methanol to form
CH3-O-CH3 methoxy methane
Methanol reacts with ethanol to form
CH3-O-CH2CH3 methoxy ethane
LecturePLUS Timberlake

39. Amides
Formed by the condensation reaction of an acid and an amine

40. Naming Amides
Alkanamide from acid name O  methanamide (IUPAC) HC–NH2  propanamide (IUPAC) CH3CH2C–NH2

41. 7) HYDROLYSIS water adds to a bond splitting it into two
Reverse of a condensation reaction
Water can add to an ester or amide bond
Ester + water makes a carboxylic acid and alcohol
Amide + water makes a carboxylic acid and amine
1-propanol

42. using alkyl halides to make amines
Ammonia and other amines are good nucleophiles

43. Substitution Reactions of Aromatic Compounds
Due to stabilization, aromatic compounds do not undergo addition reactions; they undergo substitution.
Hydrogen is replaced by substituent.

44. Substitution Reactions of Aromatic Compounds
Halogenation
Friedel-Crafts Reaction
Reactions of aromatic compounds often require a catalyst.

46. Organic Synthesis Problem set
Draw out the synthesis sequence for each molecule below using the smaller molecules listed. Show complete structures for each step. Name each intermediate and by-product. State the reaction type in each step:
Ethyl butanoate from any alkene and any alcohol.
2. ethylbenzene, from benzene, Chlorine gas and an alkane