Organic Chemistry is one of the major
branches of chemistry.
It includes the study of:
 all biological molecules
 all fossil fuels
 nearly all synthetic materials
 many domestic and industrial products such as
paints, detergents and refrigerants.
General characteristics:
 We can give each homologous series a general formula
which applies to all members of the homologous series.
For example: all members of the alkane
homologous series have the general formula
CnH2n+2, where n is the number of carbon atoms.
The alkane with five carbon atoms is called
pentane. Its formula is C5H2x5+2, which is C5H12.
All members of the alkene homologous series
have general formula CnH2n.
• have similar chemical properties
• have physical properties that vary in a
regular manner as the number of
carbon atoms increases
– Example: the alkanes
skeletal formula
– every “corner” represents a carbon
– hydrogens are implied
HYDROCARBONS
a compound of hydrogen and carbon, such as
any of those which are the chief components
of petroleum and natural gas.
IUPAC
Nomenclature of
Organic Chemistry
Alkanes
Structural formulas for the isomers of noncyclic alkanes up to C6
• hydrocarbon chains where all the bonds between
carbons are SINGLE bonds
• CnH2n+2
• draw out and write the structural formulas for
all isomers that can be formed by:
–
–
–
–
–
–
CH4
C2H6
C3H8
C4H10
C5H12
C6H14
Richard Thornley
Alkenes
Structural formulas for the isomers of the straight
chain alkenes up to C6 (10.1.7)
• alkenes have a double bond between two or more of
the carbons
• CnH2n
Naming the isomers (IUPAC) of non-cyclic
alkanes up to C6
1. Richard Thornley 3:35
2. Determine the longest carbon chain
–
1
2
3
4
5
6
Use the prefix to denote the number carbons
MethEthPropButPentHex-
Monkeys
Eat
Peeled
Bananas
Nomenclature Practice
Name this compound
CH3
H3C1 2
Cl
3 4
5
CH3
9 carbons = nonane
6
7
8
H3C9
Step #1: For a branched hydrocarbon, the longest
continuous chain of carbon atoms gives the root name
for the hydrocarbon
Nomenclature Practice
Name this compound
CH3
H3C1 2
Cl
3 4
5
CH3
6
9 carbons = nonane
CH3 = methyl
7
8
chlorine = chloro
H3C9
Step #2: When alkane groups appear as substituents, they are named
by dropping the -ane and adding -yl.
Nomenclature Practice
Name this compound
CH3
H3C1 2
Cl
3 4
5
9 carbons = nonane
CH3
6
CH3 = methyl
7
chlorine = chloro
8
H3C9
1
9 NOT
9
1
Step #3: The positions of substituent groups are
specified by numbering the longest chain of carbon
atoms sequentially, starting at the end closest to the
branching.
Nomenclature Practice
Name this compound
CH3
H3C1 2
Cl
3 4
5
CH3
9 carbons = nonane
6
CH3 = methyl
7
8
chlorine = chloro
H3C9
2-chloro-3,6-dimethylnonane
Step #4: The location and name of each substituent are
followed by the root alkane name. The substituents are
listed in alphabetical order (irrespective of any prefix),
and the prefixes di-, tri-, etc. are used to indicate
multiple identical substituents.
Naming Practice!!!
CH2
CH3 CH2 C
CH2 CH3
CH2 C
CH3
CH3
choose the correct ending
ene
CH2
CH3 CH2 C
CH2 CH3
CH2 C
CH3
CH3
determine the longest carbon chain with
the double bond
ene
CH2
CH3 CH2 C
CH2 CH3
CH2 C
CH3
CH3
assign numbers to each carbon
ene
CH2
CH2 CH3
1
CH3 CH2 C
2
5
CH2 C
3
4
6
CH3
CH3
assign numbers to each carbon
ene
CH2
CH2 CH3
1
CH3 CH2 C
2
5
CH2 C
3
4
6
CH3
CH3
attach prefix (according to # of carbons)
1-hexene
ene
CH2
ethyl
CH2 CH3
1
CH3 CH2 C
2
5
CH2 C
3
4
CH3
6
CH3
methyl
methyl
determine name for side chains
1-hexene
CH2
ethyl
CH2 CH3
1
CH3 CH2 C
2
5
CH2 C
3
4
CH3
6
CH3
methyl
methyl
attach name of branches alphabetically
2-ethyl-4-methyl-4-methyl-1-hexene
CH2
ethyl
CH2 CH3
1
CH3 CH2 C
2
5
CH2 C
3
4
CH3
6
CH3
methyl
methyl
group similar branches
2-ethyl-4-methyl-4-methyl-1-hexene
CH2
ethyl
CH2 CH3
1
CH3 CH2 C
2
5
CH2 C
3
4
CH3
6
CH3
methyl
methyl
group similar branches
2-ethyl-4,4-dimethyl-1-hexene
or 2-ethyl-4,4-dimethyl hex-1-ene
CH3 CH
CH2
propene
CH3 CH
CH3
CH3
CH
CH3
CH
C
CH3
CH CH3
2-butene
2,4-dimethyl-2-pentene
2,4-dimethyl pent-2-tene
CH3
CH2 CH
C
CH3
CH2 CH3
CH3
CH3
C
CH
CH2
a) 3,3-dimethyl-1-pentene
C
C
CH
CH3
b) same
CH3
CH3
CH2
CH
CH3
c) 4,5 dimethyl-2-hexene
CH3