Organic Chemistry Nomenclature Workbook 3.12
Organic Chemistry Nomenclature Workbook 3.12
Organic Chemistry Nomenclature Workbook 3.12
Workbook
By:
Rebekah ODonnell
Organic Chemistry Nomenclature
Workbook
By:
Rebekah ODonnell
Online:
< http://cnx.org/content/col29252/1.3/ >
This selection and arrangement of content as a collection is copyrighted by Rebekah ODonnell. It is licensed under
the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/).
Collection structure revised: May 13, 2019
PDF generated: May 18, 2019
For copyright and attribution information for the modules contained in this collection, see p. 93.
Table of Contents
1 Unbranched Alkanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2 Constitutional Isomers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3 Alkyl Substituents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4 Alkenes and Alkynes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5 Halogens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
6 Benzene and Conjugation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
7 Alcohols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
8 Ethers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
9 Aldehydes and Ketones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
10 Carboxylic acids and Esters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
11 Amines and Amides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Attributions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
iv
Unbranched Alkanes 1
An alkane is a type of hydrocarbon (a compound consisting of only carbon and hydrogen atoms). When
the carbon-carbon backbone consists only of single bonds, the hydrocarbon contains as many hydrogen atoms
saturated. Alkanes are saturated hydrocarbons.
as possible, and is therefore
Unbranched alkanes have all their carbon atoms in a single chain.
Hexane
Figure 1.1: Hexane is an unbranched, saturated alkane containing six carbon atoms.
Below is a table of the names of unbranched, saturated alkanes containing up to ten carbons, with their
condensed structural formulas, molecular formulas, and boiling points.
1
2 CHAPTER 1. UNBRANCHED ALKANES
Heptane 98
Octane 126
Nonane 151
Decane 174
Table 1.1: Table of names, condensed structural formulas, molecular formulas, and boiling points of
2) Draw the structures of these ten unbranched alkanes, using Figure 1 (hexane) as a model.
4) What is the relationship between the number of carbon atoms and the number of hydrogen atoms in an
unbranched alkane? Provide a general formula (use n for the number of carbon atoms).
5) Draw a graph of boiling points versus number of carbon atoms in unbranched alkanes.
6) How do the boiling points vary with the number of carbons? Propose an explanation for this observation.
Constitutional Isomers 1
Two alkanes
3
4 CHAPTER 2. CONSTITUTIONAL ISOMERS
Pentane
Isopentane
Neopentane
Figure 2.5
Alkyl Substituents 1
An alkane can be appended onto an existing chain to create a branched molecule. This branched piece of
substituent. A substituent made from an alkane is called an alkyl group.
the molecule is called a
Alkyl groups are named similarly to unbranched alkane chains.
Butane CH3 CH2 CH2 CH3 Butyl CH3 CH2 CH2 CH2 -
Table 3.1
Alkyl groups can also be branched. For example, there are three constitutional isomers of the butyl
substituent. In these diagrams, the negative charge on the carbon indicates the site of the bond from the
substituent to the rest of the molecule.
isobutyl
Figure 3.1
7
8 CHAPTER 3. ALKYL SUBSTITUENTS
sec-butyl
Figure 3.2
tert-butyl
Figure 3.3
When naming molecules according to the IUPAC system of substitutive nomenclature, remember prex-
parent-sux (like un-believe-able).
prex: what are the substituents?
parent: how many carbons in the parent chain?
sux: what is the family of compounds?
In the case of an alkane, the sux is -ane.
The name of this molecule is 2-methylhexane. Identify the alkyl group. Label the parent chain carbons
from 1-6.
2-methylhexane
Figure 3.4
The name of this molecule is 3-methylheptane. Identify the alkyl group. Label the parent chain carbons
from 1-7.
3-methylheptane
Figure 3.5
Identify the alkyl group in Molecule A. Label the parent chain carbons from 1-8. What is the name of
this molecule?
Molecule A
Figure 3.6
Identify the alkyl group in Molecule B. Label the parent chain carbons. What is the name of this
molecule?
Molecule B
Figure 3.7
2,3-dimethylpentane
Figure 3.8
Molecule C
Figure 3.9
4-ethyl-2-methyloctane
Figure 3.10
Molecule D
Figure 3.11
4-isopropylnonane
Figure 3.12
Molecule E
Figure 3.13
cyclobutane
Figure 3.14
Molecule F
Figure 3.15
methylcyclobutane
Figure 3.16
1-ethyl-2-methylcyclohexane
Figure 3.17
Molecule G
Figure 3.18
Write the steps that you use to name an alkane, in order, as instructions for a student who doesn't know
how to do it.
Draw any alkane and go through the steps in naming your molecule.
An alkane is a saturated hydrocarbon, meaning that the molecule contains all the possible hydrogen atoms
because all the carbon-carbon bonds are single bonds. If one of those carbon-carbon bonds is a double bond,
the resulting hydrocarbon is unsaturated and called an alkene.
This alkene is named propene.
propene
Figure 4.1
If one of the carbon-carbon bonds is a triple bond, the resulting hydrocarbon is called an alkyne.
This alkyne is named ethyne.
ethyne
Figure 4.2
17
18 CHAPTER 4. ALKENES AND ALKYNES
Molecule A
Figure 4.3
The double or triple bond is called a functional group, and is often the site where chemical reactions
occur. Like a substituent, it is specied in the molecular name. When naming molecules according to the
IUPAC system of nomenclature, remember prex-parent-sux (like un-believe-able).
prex: what are the substituents?
parent: how many carbons? If there is a double or triple carbon-carbon bond in the molecule, both
carbons in that bond must belong to the parent carbon chain, even if that chain does not have the greatest
number of carbons.
sux: what is the family of compounds?
This molecule is named 2-pentene.
2-pentene
Figure 4.4
Molecule B
Figure 4.5
Molecule C
Figure 4.6
4-methyl-2-pentene
Figure 4.7
Molecule D
Figure 4.8
3-isobutyl-1-octyne
Figure 4.9
Molecule E
Figure 4.10
cyclohexene
Figure 4.11
Molecule F
Figure 4.12
4-methylcyclohexene
Figure 4.13
Molecule G
Figure 4.14
1,3-pentadiene
Figure 4.15
Molecule H
Figure 4.16
The location of substituents relative to the double bonds can lead to a type of constitutional isomer
known as a positional isomer.
The name of this molecule is 5-methyl-1,3-cyclohexadiene.
5-methyl-1,3-cyclohexadiene
Figure 4.17
Molecule I
Figure 4.18
Double or triple carbon-carbon bonds are rigid and planar. Since the carbons cannot rotate freely around
the bond, cis/trans isomers are common, and the orientation may be important for chemical reactions.
Figure 4.19
Write the steps that you use to name an alkene and an alkyne, in order, as instructions for a student
who doesn't know how to do it.
Draw any alkene or alkyne and go through the steps in naming your molecule.
Halogens 1
The halogens are elements belonging to Group 7A. Fluorine, chlorine, bromine, and iodine can
be added to hydrocarbons through reactions with their diatomic forms or when bound to hydrogen as
hydrogen halides.
When a halogen atom is bound to an otherwise saturated carbon atom, the molecule is known as an
alkyl halide.
Chlorine Cl chloro-
Bromine Br bromo-
Iodine I iodo-
Table 5.1
When naming molecules according to the IUPAC system of nomenclature, remember prex-parent-
sux (like un-believe-able).
prex: what are the substituents?
parent: how many carbons?
sux: what is the family of compounds?
This molecule is named 2-chlorobutane.
1 This content is available online at <http://cnx.org/content/m76446/1.3/>.
27
28 CHAPTER 5. HALOGENS
2-chlorobutane
Figure 5.2
Molecule A
Figure 5.3
2-uoro-3-methylpentane
Figure 5.4
4-iodo-2-methylhexane
Figure 5.5
Molecule B
Figure 5.6
1-chloro-2-butene
Figure 5.7
5-uoro-2-hexene
Figure 5.8
Molecule C
Figure 5.9
5-uoro-1,3-cyclohexadiene
Figure 5.10
Molecule D
Figure 5.11
Write the steps that you use to name an alkyl halide, in order, as instructions for a student who doesn't
know how to do it.
Draw any alkyl halide and go through the steps in naming your molecule.
benzene
Figure 6.1
We would expect to name this molecule 1,3,5-cyclohexatriene and see its double bonds react like other
double bonds. However, these double bonds do not react in the same way as double bonds in a standard
alkene. Observe the result of the below experiment under the appropriate reaction conditions.
33
34 CHAPTER 6. BENZENE AND CONJUGATION
Figure 6.2
This surprising stability of the double bonds in the benzene ring is not due to the cyclic arrangement
of the carbon chain. Under the appropriate reaction conditions, we see the following results for adding
hydrogen across the double bonds of the molecules below.
Figure 6.3
Double 1.34
Benzene 1.4
Table 6.1
Therefore, the three double bonds of the benzene ring are not true double bonds. The electrons are
shared across all of the carbons in the ring, an arrangement called conjugation which is better represented
by the below structure.
Figure 6.4
When depicting benzene rings using the double bond drawing, remember that the ring is a hybrid between
two equally likely resonance structures.
Figure 6.5
1-chlorobenzene
Figure 6.6
When a benzene ring has two substituents, they are named based upon their position to each other
rather than by numbers.
o-dichlorobenzene
m-chloromethylbenzene
p-chlorouorobenzene
Molecule A
Figure 6.10
2-phenyldecane
Figure 6.11
Molecule B
Figure 6.12
Conjugation is not limited to cyclic structures. One of the two molecules below does not react with
halogen halides under standard reaction conditions. Which molecule do you predict is the more stable one?
Why? What prediction would you make about the lengths of its carbon-carbon bonds?
Figure 6.13
Write the steps that you use to name a benzene derivative or a molecule containing a benzene ring as a
substituent, in order, as instructions for a student who doesn't know how to do it.
Draw any benzene-containing molecule and go through the steps in naming your molecule.
Alcohols 1
In organic chemistry, any alkyl group can be abbreviated as R. An alcohol, in which a hydroxy (-OH)
group is attached to a carbon of the alkyl group, can be abbreviated as R-OH.
The name of this molecule is ethanol.
ethanol
Figure 7.1
Molecule A
Figure 7.2
41
42 CHAPTER 7. ALCOHOLS
2-butanol
Figure 7.3
6-isopropyl-5-nonanol
Figure 7.4
Molecule B
Figure 7.5
3-propyl-2-octanol
Figure 7.6
Molecule C
Figure 7.7
3-uorocyclohexanol
Figure 7.8
Molecule D
Figure 7.9
4-hexen-2-ol
Figure 7.10
Molecule E
Figure 7.11
2,3-pentanediol
Figure 7.12
Molecule F
Figure 7.13
Two phenols
Figure 7.14
2-chlorophenol / o-chlorophenol
Figure 7.15
Molecule G
Figure 7.16
Ethers 1
In organic chemistry, any alkyl group can be abbreviated as R. An ether, in which the carbons of two
alkyl groups are linked to the same oxygen, can be abbreviated as R-O-R.
This molecule is often referred to simply as ether. Its common name is diethyl ether, and its IUPAC
name is ethoxyethane.
ethoxyethane
Figure 8.1
The common name of this molecule is ethyl methyl ether, and its IUPAC name is methoxyethane.
methoxyethane
Figure 8.2
49
50 CHAPTER 8. ETHERS
Molecule A
Figure 8.3
2-methoxy-3-methylbutane
Figure 8.4
Molecule B
Figure 8.5
4-butoxy-2-butanol
Figure 8.6
Molecule C
Figure 8.7
A carbonyl group consists of a carbon atom double-bonded to an oxygen atom, written as C=O. Alde-
hydes and ketones are two compounds which contain the carbonyl group.
aldehyde
53
54 CHAPTER 9. ALDEHYDES AND KETONES
ketone
Aldehydes and ketones are constitutional isomers. For example, the aldehyde and ketone below
both have the molecular formula C3 H6 O.
C3H6O
Figure 9.3
The simplest aldehyde is methanal, commonly known as formaldehyde, and used as a preservative.
methanal
Figure 9.4
butanal
Figure 9.5
Molecule A
Figure 9.6
5-methylhexanal
Figure 9.7
Molecule B
Figure 9.8
3-ethyl-4-methylhexanal
Figure 9.9
Molecule C
Figure 9.10
3-pentenal
Figure 9.11
Molecule D
Figure 9.12
A well-known ketone is 2-propanone, commonly known as acetone, and used as a nail polish remover.
2-propanone
Figure 9.13
2-pentanone
Figure 9.14
Molecule E
Figure 9.15
5-ethyl-2-heptanone
Figure 9.16
Molecule F
Figure 9.17
6-chloro-4-ethyl-3-heptanone
Figure 9.18
Molecule G
Figure 9.19
3-bromocyclohexanone
Figure 9.20
Molecule H
Figure 9.21
4-hydroxy-2-butanone
Figure 9.22
Molecule I
Figure 9.23
5-chloro-4-oxohexanal
Figure 9.24
Molecule J
Figure 9.25
What additions do we make to our existing naming rules to name aldehydes and ketones?
Write the steps that you use to name an aldehyde or ketone in order, as instructions for a student who
doesn't know how to do it.
Draw any aldehyde or ketone and go through the steps in naming your molecule.
A carbonyl group consists of a carbon atom double-bonded to an oxygen atom, written as C=O. When a
hydroxy (-OH) group is also bound to the carbonyl carbon, the resulting group is known as a carboxy
group. Carboxylic acids contain the carboxy group, and one type of carboxylic acid derivative is an
ester.
carboxylic acid
Figure 10.1
67
68 CHAPTER 10. CARBOXYLIC ACIDS AND ESTERS
ester
Figure 10.2
Carboxylic acids are often abbreviated as R-COOH or R-CO2 H. Some simple carboxylic acids, such
as acetic acid and benzoic acid, are referred to primarily by their common names.
Figure 10.3
The common name of this molecule is valeric acid. Its formal name is pentanoic acid.
pentanoic acid
Figure 10.4
The common name of Molecule A is caprylic acid. What is the formal name of Molecule A?
Molecule A
Figure 10.5
hexanedioic acid
Figure 10.6
Molecule B
Figure 10.7
cyclohexanecarboxylic acid
Figure 10.8
Molecule C
Figure 10.9
1,2-benzenedicarboxylic acid
Figure 10.10
Molecule D
Figure 10.11
4-bromopentanoic acid
Figure 10.12
Molecule E
Figure 10.13
2-hydroxybutanoic acid
Figure 10.14
Molecule F
Figure 10.15
3,6-dioxo-4-hydroxyhexanoic acid
Figure 10.16
Molecule G
Figure 10.17
Esters are often manufactured to provide fragrance. One example is isobutyl methanoate, which smells
like raspberries.
isobutyl methanoate
Figure 10.18
The process of esterication involves adding an alcohol to a carboxylic acid in the presence of hydrogen
ions.
esterication
Figure 10.19
To name an ester, rst we name the alcohol used, and then the carboxylic acid. Below is shown the
esterication reaction of ethanol and propanoic acid to create ethyl propanoate.
Figure 10.20
Molecule H
Figure 10.21
Molecule I
Figure 10.22
dimethylbutanedioate
Figure 10.23
Molecule J
Figure 10.24
2-chloroethyl propanoate
Figure 10.25
Molecule K
Figure 10.26
2-bromopropyl 4-chlorobutanoate
Figure 10.27
Molecule L
Figure 10.28
What additions do we make to our existing naming rules to name carboxylic acids and esters?
Write the steps that you use to name a carboxylic acid in order, as instructions for a student who doesn't
know how to do it.
Draw any carboxylic acid and go through the steps in naming your molecule.
Write the steps that you use to name an ester in order, as instructions for a student who doesn't know
how to do it.
Draw any ester and go through the steps in naming your molecule.
Figure 11.1
Despite the complexity of the below molecule, because the nitrogen is directly bound to two hydrogens
and only one R group, it is a primary amine.
83
84 CHAPTER 11. AMINES AND AMIDES
Figure 11.2
There are multiple substitutive nomenclatures for naming amines, with the two most common being
IUPAC and Chemical Abstract Service. Both will be described below.
This molecule is named 2-pentanamine (CAS) or 2-aminopentane (IUPAC).
Figure 11.3
Molecule A
Figure 11.4
Figure 11.5
Molecule B
Figure 11.6
Figure 11.7
Molecule C
Figure 11.8
This molecule is named 4-amino-2-pentanone (CAS) or 4-aminopentan-2-one (IUPAC). Number the car-
bons.
Figure 11.9
Molecule D
Figure 11.10
Figure 11.11
Molecule E
Figure 11.12
An amide is a carboxylic acid derivative in which the carboxyl -OH has been replaced with
an amino or substituted amino group. Amides are also described as primary, secondary, or tertiary
depending on the number of R groups bound directly to the nitrogen.
Figure 11.13
The naming of simple amides is based on the carboxylic acid nomenclature, and keeps the same name in
the CAS and IUPAC systems.
The name of this molecule is 3-methylbutanamide.
3-methylbutanamide
Figure 11.14
Molecule F
Figure 11.15
N-methylbenzamide
Figure 11.16
Molecule G
Figure 11.17
What additions do we make to our existing naming rules to name amines and amides, in the substitutive
naming system that you use?
Write the steps that you use to name an amine in order, as instructions for a student who doesn't know
how to do it.
Draw any amine and go through the steps in naming your molecule.
Write the steps that you use to name an amide in order, as instructions for a student who doesn't know
how to do it.
Draw any amide and go through the steps in naming your molecule.
C carbonyl, 9(53)
6(33), 7(41), 8(49), 9(53), 10(67),
11(83)
carboxylic, 10(67)
chemistry, 1(1), 3(7), 4(17), 5(27), O organic, 1(1), 3(7), 4(17), 5(27), 6(33),
6(33), 7(41), 8(49), 9(53), 10(67), 7(41), 8(49), 9(53), 10(67), 11(83)
11(83)
conjugation, 6(33) S saturated, 1(1)
ether, 8(49)
Attributions
Collection: Organic Chemistry Nomenclature Workbook
Edited by: Rebekah ODonnell
URL: http://cnx.org/content/col29252/1.3/
License: http://creativecommons.org/licenses/by/4.0/
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