Organic Chemistry
Organic Chemistry:
The chemistry of carbon and
carbon-based compounds
Organic Chemistry in everyday life:
Smells & tastes: fruits, chocolate, fish, mint
Medications: Aspirin, Tylenol, Decongestants, Sedatives
Addictive substances: Caffeine, Nicotine, Alcohol, Narcotics
Hormones/Neurotransmitters: Adrenaline, Epinephrine
Food/Nutrients: Carbohydrates, Protein, Fat, Vitamins
Genetics: DNA, RNA
Consumer products: Plastics, Nylon, Rayon, Polyester
Big Idea in Organic Chemistry
Structure controls Function
Each functional group has predictable reactivity
Names of Linear Alkanes and Alkyl Substituents
# of
C atoms
Alkane
1
CH4
2
CH3CH3
3
CH3CH2CH3
4
CH3CH2CH2CH3
Alkyl substituents
methane
ethane
propane
butane
5
pentane
6
hexane
7
heptane
8
octane
9
nonane
10
decane
-CH3
-CH2CH3
-CH2CH2CH3
methyl
ethyl
propyl
etc.
Root: number of C atoms
Suffix: functional group
(-ane for alkanes)
(-yl for alkyl groups)
H H H H
H
H C H
H
H
H H H H
Methane
CH4
Butane
C4H10
H H H H
H
R?
C C C C H
C H
R
?
C C C C H
H
H H H H
Methyl
-CH3
Butyl
-C4H9
Where R = any other C atom or arrangement of C atoms
Naming Practice
Expanded Structure
H H H
Line Structure
H
H C C C C H
H H
H
H C H
H
butane
2 - methylbutane
H H CH3
H
C C C
6
1
52
43
Naming Practice
CH3
Line Structure
H H C H
3
4
H C H
25
H C H
16
H
4,4-dimethylhexane
3,3-dimethylhexane
Lowest sum of numbers
is correct
Cycloalkanes
Formula
CnH2n
Condensed Structural
Formula
Geometric
Formula
Name
Cyclopropane
Cyclobutane
Cyclopentane
Cyclohexane
Timberlake, Chemistry 7th Edition, page 388
Hydrocarbons
Number of
Carbon Atoms
Alkanes
CnH2n + 2
Alkenes
CnH2n
Alkynes
CnH2n-2
1
CH4
Methane
____
_______
____
_______
2
C2H6
Ethane
C2H4
Ethene
C2H2
Ethyne
3
C3H8
Propane
C3H6
Propene
C3H4
Propyne
4
C4H10
Butane
C4H8
Butene
C4H6
Butyne
5
C5H12
Pentane
C5H10
Pentene
C5H8
Pentyne
6
C6H14
Hexane
C6H12
Hexene
C6H10
Hexyne
7
C7H16
Heptane
C7H14
Heptene
C7H12
Heptyne
8
C8H18
Octane
C8H16
Octene
C8H14
Octyne
9
C9H20
Nonane
C9H18
Nonene
C9H16
Nonyne
10
C10H22
Decane
C10H20
Decene
C10H18
Decyne
Classified according to functional group
Types of Organic Compounds
Alkane
Alcohol
Carboxylic acid
O
OH
OH
Alkene
Ether
Amine
NH2
O
Alkyne
C
Ketone
Amide
O
O
C
NH2
Haloalkane
Aldehyde
Amino acid
O
O
Cl
Br
H
H2N
OH
Alcohols (R-OH)
Methanol
(methyl alcohol)
Ethanol
R = -CH3
‘methyl’
R = -CH2CH3 ‘ethyl’
Timberlake, Chemistry 7th Edition, page 437
(ethyl alcohol)
Aldehydes and
Ketones
O
Aldehyde
Ketone
Acetaldehyde
ethanal, ethyl aldehyde
O
(CH3CH)
Timberlake, Chemistry 7th Edition, page 453
Formaldehyde
methanal
(CH2O)
R-C-H
O
R-C-R'
Acetone
dimethyl ketone, 2-propanone
(CH3COCH3)
Dimethyl Ether
Dimethyl ether
– C2H6O
– Flammable
– anesthesia
Timberlake, Chemistry 7th Edition, page 446
R- Functional Groups
-CH3
methyl
-CH2CH3
ethyl
-CH2CH2CH2CH3
butyl
H
sec-butyl
CH3CHCH2CH3
-CH2CH2CH3
propyl
H
– CH2 – C – CH3
isobutyl
CH3
H
isopropyl
CH3CCH3
CH3
– C – CH3
CH3
tert-butyl
Alkenes and Alkynes
• Alkene
– Double bonds
ethene
• Alkynes
A ball-and-stick model of ethene C2H4,
the simplest alkene.
– Triple bonds
ethyne (acetylene)
A ball-and-stick model of acetylene
(IUPAC name ethyne)
Timberlake, Chemistry 7th Edition, page 409
Aliphatic Hydrocarbons
Alkane
Alkene
Alkyne
Alkadiene
CnH2n - 2
General
formula
CnH2n + 2
CnH2n
CnH2n - 2
Typical
structural
formula
–C–C–C–C–
–C=C–C–C–
–C =C–C–C–
–C=C–C=C–
butane
1-butene
1-butyne
1,3-butadiene
all single bonds
one double bond
one triple bond
two double bonds
-ane
-ene
-yne
-diene
Carbon-carbon
bond type
Naming
suffix
Benzene
An Aromatic Compound
– C6H6
– Resonance structures
– Kekule’s dream
Drawing
Organic
Structures
Shortcuts make structures easier & faster to draw
Butane: C4H10
Lewis Structure
H
H
H
H
H
C
C
C
C
H
H
H
H
Carbon Atoms
H
Condensed Structures
CH3 CH2 CH2 CH3
CH3CH2CH2CH3
CH3(CH2)2CH3
Line Structure
• Only shows bonds
• C atoms assumed at each end
and intersection of bonds
• H atoms not shown
• Assume 4 bonds to each C
• Fulfill C’s 4 bonds by adding H’s
Common Names of other Alkyl Substituents
Remember that R = any carbon chain
R
3 carbons
CH CH3
R
CH3
isopropyl
alphabetized as “i”
“iso” indicates symmetry
R
CH2 CH CH3
R
isobutyl
CH3
4 carbons
2o
R
alphabetized as “i”
CH CH2 CH3 R
2o
CH3
sec-butyl
alphabetized as “b”
Secondary carbon
CH3
R
3o
C
CH3
CH3
R
3o
tert-butyl
alphabetized as “b”
Tertiary carbon
Primary, Secondary, Tertiary Alcohols
Primary (1o)
Alcohol
Carbon attached
to OH group
H
R1
Alkyl
group
C
Secondary (2o)
Alcohol
OH
R1
H
Tertiary (3o)
Alcohol
R2
C
R2
OH
R1
C
H
R3
CH3
CH3
OH
Examples:
H
CH3
C
OH
CH3
C
OH
CH3
C
H
H
CH3
1o
2o
3o
(One alkyl group)
(Two alkyl groups)
OH
(Three alkyl groups)