Handout: Naming Organic Compounds
A. IUPAC Naming
General Rules:
Prefix + Parent + Suffix
Substituents
Family
Longest carbon chain
Some Substituent Names
Substituent
Substituent Name
Group
Hydrocarbon
alkyl
with single
bonds only
1. Name parent+suffix: longest carbon chain + family suffix.
2. Number carbons in parent chain: Begin numbering from end
that meets specified criteria (*See Nomenclature Chart).
3. Name prefix: substituent position #s and names (grouping
repeated substituents together using di-, tri-, etc).
4. Write full name, listing substituents in alphabetical order
(ignoring di-, tetra- in alphabetizing).
Methane
Ethane
Propane
Butane
Pentane
Hexane
Heptane
Octane
Nonane
Decane
H2
C
H 3C
methyl
ethyl
CH 3
CH 3
C
H
H 3C
isopropyl
H 3C
C
H
C
H
H2
C
isobutyl
H2
C
CH 3
sec-butyl
CH 3
H 3C
C
CH 3
O
C
Name
H 3C
H 3C
Name Format: #–substituent–#–substituentparentsuffix
Some Parent Alkane Names
No. of
Structure
Carbons
1
CH4
2
CH3CH3
3
CH3CH2CH3
4
CH3 CH2CH2CH3
5
CH3 CH2CH2CH2CH3
6
CH3 CH2CH2CH2CH2CH3
7
CH3CH2CH2CH2CH2CH2CH3
8
CH3CH2CH2CH2CH2CH2CH2CH3
9
CH3CH2CH2CH2CH2CH2CH2CH2CH3
10
CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3
Specific Examples
acyl
R
(Ends with –oyl,
except for acetyl)
–OR
alkoxy
O
formyl
tert-butyl
O
O
C
C
H 3C
H 3C
acetyl
propanoyl
H 3C
H 3C
methoxy
C
H2
H2
C
ethoxy
HC
O
keto
C
–OH
-NO2
–NH2
-X (halogen)
hydroxy
nitro
amino
halo
-Cl chloro -Br bromo
-I iodo
phenyl
H. Kim for Chem 30B
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B. Common Names
Some Widely-Used Common Names
Compound
Common Name
CH2=CH2
ethylene
CH3CH=CH2
propylene
HC
CH
acetylene
O
acetone
C
H 3C
IUPAC Name
1-ethene
1-propene
1-ethyne
2-propanone
CH 3
O
formaldehyde
methanal
acetaldehyde
ethanal
formic acid
methanoic acid
acetic acid
ethanoic acid
propionic acid
propanoic acid
butyric acid
butanoic acid
CH2
O
CH
H 3C
O
HC
OH
O
H 3C
C
OH
O
H 3C
C
H2
C
OH
O
H 3C
H2
C
C
H2
C
OH
H. Kim for Chem 30B
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Nomenclature Chart for Organic Compounds (From HIGHEST TO LOWEST naming priority)
FAMILY
Carboxylic acid
Ester
Amides
Aldehydes
Ketones
Alcohol
PARENT
Parent is longest
carbon chain
containing carboxylic
acid. Derive name
from parent alkane.
Name of alkyl group
that replaced -H in
-COOH + name
derived from parent
acid, replacing –ic acid
with –ate
Derive name from
parent carboxylic acid,
replacing –oic acid
with –amide.
Derive name from
parent alkane.
SUFFIX
–oic acid
(-dioic acid
for dicarboxylic acid;
-enoic acid
for unsaturated acid)
–ate
–amide
NUMBERING
Begin at carbonyl C.
NOTES
Common names are often used
(C next to COOH group is
designated as “α”).
EXAMPLES
[Salts: cation + name derived
from parent acid, replacing –ic
acid with –ate ]
2-chloropropanoic acid or
α-chloropropionic acid (common)
O
H 3C
H
C
C
OH
Cl
Begin at carbonyl C.
Begin at carbonyl C.
Common names are often used:
name of alkyl group that
replaced -H in -COOH + name
derived from common name of
parent acid, replacing –ic acid
with –ate
Alkyl substituents on nitrogen
start with “N-.”
O
H 3C
H2
C
H2
C
C
O
H2
C
CH 3
ethyl butanoate or
ethyl butyrate (common)
H 3C
O
CH 3
C
N
CH 3
N,N-dimethylacetamide
–al
Derive name from
parent alkane. Parent
name starts with
position # of carbonyl
C.
–one
Parent is longest
carbon chain
containing OH. Parent
name starts with
position # of the C
with OH.
–ol
(-diol,
-triol, etc.)
Begin at carbonyl C.
Begin at end nearer
to carbonyl C.
Begin at end nearer
to OH group.
Common names are often used
for simplest aldehydes, ending
with “–aldehyde.”
Common names are often used
for simple ketones: names of
two alkyl groups + “ketone.”
Cyclic alcohols: Parent name
begins with “cyclo” (no need to
start parent name with “1”).
Begin numbering at C with OH,
and number to give
substituents lowest numbers.
CH 3
H 3C
C
H
O
H2
C
C
H
3-methylbutanal or
β-methylbutyraldehyde (common)
O
H 3C
H2
C
H2
C
C
CH 3
2-pentanone or
methyl propyl ketone (common)
CH 3
H 3C
C
H
OH
H2
C
H2
C
C
H
CH 3
5-methyl-3-hexanol
OH
CH 3 2-methylcyclohexanol
OH
H 3C
Thiols
–thiol
Name in same way as alcohols,
except end with “-thiol.”
H 3C
C
H
H2
C
H2
C
SH
H2
C
OH
1,3-butanediol
ethanethiol
H. Kim for Chem 30B
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FAMILY
Amines
Alkenes
Alkynes
Alkanes
Ethers
PARENT
SUFFIX
–amine
Parent is longest
carbon chain
containing the double
or triple bond. Parent
name starts with
position number of
multiple bond.
May need cis/trans
designation.
–ene
–yne
Parent is longest
carbon chain.
–ane
The alkoxy group –OR
is treated as the
substituent (Alkane or
another functional
group is the parent).
(-diene,
-triene, etc.)
NUMBERING
Begin at end closer
to multiple bond.
(If multiple bonds
are equidistant,
give smaller
number to first
branch point).
Then give smallest
numbers possible
to substituents.
Begin at end nearer
to branch point.
Then give smallest
numbers possible
to substituents.
NOTES
1° amines, and 2°, 3° amines
with same R groups on N: Treat
alkyl groups attached to
nitrogen as substituents. For
same substituents, use “di” and
“tri.”
2°, 3° amines with different R
groups on N: Parent amine is
the one with largest R group;
name other groups as
substituents, starting with N-.
[Ions derived from amines:
Replace –amine with
–ammonium.]
Cyclic alkenes: Parent name
begins with “cyclo” (no need to
start parent name with “1”).
Number multiple bonds 1 and
2, in direction to give first
substituent the next smaller
possible number.
EXAMPLES
H2
C
H 3C
H2
C
NH 2
(1°)
propylamine
H 3C
H2
C
H2
C
N
H 2C
(3° with same R
groups)
CH 3
CH 3
triethylamine
H2
C
H 3C
H2
C
H
N
CH 3
(2° with
diff’t R groups)
N-methylpropanamine
H 3C
H2
C
CH2CH2CH 3
C
C
H
CH 3
cis-4-methyl-3-heptene
H 3C
H2
C
H2
C
H2
C
C
C
CH 3
2-heptyne
CH 3
4-methylcyclohexene
Cyclic alkanes: Parent name
begins with “cyclo.” Give
smallest number to substituent
that comes first in alphabetical
order. Number in direction to
give second substituent the
smaller possible number. (If
single substituent, don’t need
“1-.”)
Common names are often used
for simple ethers: two R groups
+ “ether.”
Common names are used for
cyclic ether compounds.
CH 3
H 3C
C
H
H2
C
H2
C
H
C
H 2C
CH 3
CH 3
4-ethyl-2-methylhexane
H2
C
H 3C
CH 3
1-ethyl-3-methylcyclohexane
H 3C
H2
C
O
H2
C
H2
C
CH 3
1-ethoxypropane or
ethyl propyl ether (common)
H 3C
H2
C
O
H2 H2 H2
C C C
OH
3-ethoxypropanol
H. Kim for Chem 30B
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Haloalkanes (or
Alkyl Halides)
Halogen atom is
treated as substituent
(Alkane or another
functional group is the
parent).
Common names are often used,
in format “alkyl halide.”
Aromatic Nomenclature (*Functional group priority is same in aromatic and aliphatic nomenclature.)
FAMILY
PARENT
SUFFIX
NUMBERING
NOTES
Benzene
“benzene” or common
For di-substituted
Common names for substituted
name for substituted
benzenes, o, m, p
benzenes are often used
benzene
typically used for
(accepted by IUPAC):
CH 3
positions of
OH
substituents.
o-
Toluene
Phenol
H 3C
H2
C
Br
1-bromoethane or
ethyl bromide (common)
EXAMPLES
NO 2
Cl
m-chloronitrobenzene
OH
O
O
CH
C
OH
O2N
p-nitrophenol
mBenzaldehyde
Benzoic acid
NH 2
pAniline
H. Kim for Chem 30B
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