Download N - Clayton State University

John E. McMurry
www.cengage.com/chemistry/mcmurry
Lecture 02
Drawing Structures,
Functional Groups,
Nomenclature, Isomerism
Paul D. Adams • University of Arkansas
Representing Organic
Compounds

Compounds can be represented in many different ways.
 Some representations provide information about the structure, while
others do not.
 Molecular Formula: Number of atoms of each element in one
molecule of a compound (no structural information).
 Ex. C6H14
 Empirical Formula: Relative ratio’s of elements present.


Ex. CH2O could be CH2O or C2H4O2.
Line bond (Kekule) Structures: Show all atoms and bonds.
 Condensed Structures: Show all atoms, but only show bonds when
necessary.
 Skeletal Structures: Show C-C bonds and all atoms that are not C or
H.
Representing Organic
Compounds
Structural
Formula
Condensed
Structural
Formula
H
H
H
H
H
C
C
C
C
H
H
H
H
Also called Line-bond
or Kekule structures.
CH3CH2CH2CH3
CH3(CH2)2 CH3
Learn this quickly, it
will save you much
time.
Skeletal
Structure
Molecular
Formula
H
C4H10
3.2 Alkanes and Alkane
Isomers
 Alkanes: Compounds with C-C single bonds and C-H bonds




only (no functional groups)
Connecting carbons can lead to large or small molecules
The formula for an alkane with no rings in it must be CnH2n+2
where the number of C’s is n
Alkanes are saturated with hydrogen (no more can be
added
They are also called aliphatic compounds
Isomerism
Isomers: Compounds that have identical molecular formulas, but
different arrangement of atoms.
 Constitutional (Structural) isomers: Same formula, different
arrangement.
 Stereoisomers: Same formula, same arrangement, different 3D
orientation.
Ex. Structural Isomers of C2H6O. At room temp:
 Ethyl alcohol is a liquid, completely soluble in water.
 Dimethyl ether is a gas, partially soluble in water.
Seager SL, Slabaugh MR, Chemistry for Today: General, Organic and Biochemistry, 7 th Edition, 2011
Isomerism
H
H
C
H
H
H
H
C
C
H
H
H
H
H
C
C
C
H
 Constitutional (Structural isomers): Same formula,
H
H
different arrangement.
H
H
H
H
H
H
H
C
H
H
C
H
H
C
H
n-Butane
H
H
C
C
H
H
H
H
H
C
C
C
H
H
H
H
isobutane
H
3D Conformations of Alkanes

Molecules are not static, but in constant motion.
 They, twist, turn, bend, vibrate, rotate around C-C bonds.
 Rotation produces different conformations.
H3C
H3C
H3C
CH3
CH3
CH3
H3C
H3C
H3C
CH3
CH3
CH3
Seager SL, Slabaugh MR, Chemistry for Today: General, Organic and Biochemistry, 7 th Edition, 2011
Recognizing Isomers
• Different conformations are not the same as structural
isomers (butane, isobutene)
• Two structures are STRUCTURAL ISOMERS only if bonds have
to be broken and remade to convert one to the other.
Constitutional Isomers
Alkyl Substituents
 Alkyl groups: substituents (branches) on parent alkane.
#C
1
2
3
4
5
6
7
8
9
10
Name
methane
ethane
propane
butane
pentane
hexane
heptane
octane
nonane
decane
Alkyl
Group
methyl
ethyl
propyl
butyl
pentyl
hexyl
heptyl
octyl
nonyl
decyl
Isomers?
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
substituent
parent
Alkyl Groups (Continued)
Classifications of Carbons,
Hydrogens
Common Alkyl Groups
Parent alkane
methane
ethane
propane
n-butane
isobutene
Parent structure
CH4
CH3CH3
CH3CH2CH3
Alkyl group structure
--CH3
--CH2CH3
--CH2CH2CH3
Alkyl group name
methyl
ethyl
propyl
CH3CH2CH2CH3
|
CH3CHCH3
--CH2CH2CH2CH3
isopropyl
butyl
CH3
|
CH3CHCH3
|
CH3CHCH2CH3
CH3
|
--CH2CHCH3
CH3
|
CH3CCH3
|
sec-butyl
Isobutyl
t-butyl
3.4 Naming Alkanes

Compounds are given systematic names by a process that uses
substituent
parent
3-methylhexane
4-ethyl-3-methylheptane
Naming Alkanes (Continued)
 Find the longest continuous C chain. This is the Parent.
If 2 different chains of equal length are present, the
parent is the one with the MOST branch points.
 Number the atoms in the parent chain.
 Begin numbering at the end nearest the 1st branch
point.
 If 1st point is the same at either end, begin at end
nearest the 2nd, 3rd branch points.
 We want to label this so that branch points are the
lowest numbers possible.
 If the numbering is the same in both directions, then
use alphabetical order to break the tie.

Naming Alkanes (Continued)
 Identify and number the substituents.




Assign a number to each substituent based on carbon
number in parent chain.
Two substituents on the same carbon (not 3) get the
same number.
If both substituents are the same, use the prefix di-.
If structure has multiple identical substituents, put them
altogether in the name. For example: 2,3,4,5,6pentamethyloctane.
Naming Alkanes (Continued)
 Write name as a single word.





Separate prefixes with hyphens.
Use commas (no spaces) to separate numbers.
If 2 or more different substituents are present, cite in
alphabetical order.
Multiplier prefixes (di-, tri-, tetra-, penta-, etc.) are NOT
used for alphabetizing.
The prefixes sec- and t- are NOT used for
alphabetizing, but iso- IS used for alphabetizing.
Naming Alkanes (Continued)
 When substituents are alphabetized, iso- and
cyclo are used as part of the alkyl group name,
but the hyphenated prefixes are not (except for
complex substituents).
 Thus isobutyl is alphabetized with i, but n-butyl,
tert-butyl, and sec-butyl are alphabetized with b.
Examples: Naming Alkanes
H3C
Cl
H3C
H3C
CH3
CH3
CH3
H3C
CH3
H3C
H3C
CH3
CH3
CH3
CH3
CH3
CH3
H3C
CH3
CH3
H3C
H3C
Cl
CH3
CH3
H3C
CH3
H3C
CH3
H3C
CH3
CH3
CH3
H3C
CH3
H3C
CH3
Br
CH3
Br
Examples: Naming Alkanes
H3C
Cl
H3C
H3C
CH3
CH3
CH3
H3C
CH3
5-sec-butylnonane
H3C
CH3
CH3
CH3
2-chloro-2,4-dimethylpentane
H3C
CH3
CH3
5-sec-butyl-4-methylnonane
CH3
H3C
CH3
CH3
H3C
H3C
Cl
CH3
2,2-dimethylbutane
CH3
3-ethyl-3-methylpentane
1-chloro-3-isopropylcyclopentane
H3C
CH3
H3C
CH3
H3C
CH3
CH3
CH3
1,2,4-trimethylcyclohexane
H3C
CH3
H3C
CH3
Br
Br
CH3
2,2,4,6,6-pentamethylheptane
3,5,dibromo-4-ethylheptane
Complex Substituents
(method 1)
 Complex alkyl groups are named by using the
longest carbon chain starting at the point of
attachment to the main chain(this is Carbon 1).
 Continue to name as if this were a mini-tree
(same rules for alkanes).
CH2CH3
1
2
CH3
3
CH CH CH3
CH3
a (1-ethyl-2-methylpropyl) group
1
C
2
CH2
CH3
3
CH
4
CH3
CH3
a (1,1,3-trimethylbutyl) group
When naming involves complex substituents, the first letter in the
complex substituent, regardless of type, is used for alphabetizing
Complex Substituents
(method 2)
 Complex alkyl groups are named by using the longest
carbon chain, but not necessarily starting at the point of
attachment.
 Number chain so first branch gets lowest number, and
include number indicating the point of attachment to
main chain.
Method 1
5-(1-ethyl-2-methylpropyl) decane
Method 2
5-(2-methylpentan-3-yl)decane
When naming involves complex substituents, the first letter in the complex
substituent, regardless of type, is used for alphabetizing
Naming Complex
Substituents
Naming Complex
Substituents
3-ethyl-7-methyl-5-(2methylbutyl)nonane
3-ethyl-4,6-dimethyl-5(1-methylbutyl)nonane
7-ethyl-2,6-dimethyl-5(1-methylbutyl)nonane
3,7-diethyl-2,4,6-trimethyl5-(3-methylbutyl)nonane
7-ethyl-2,4,6-trimethyl-5(1-methylbutyl)nonane
4,5-diisobutyl-2,2,6,7tetramethyloctane
4.1 Naming Cycloalkanes
 Cycloalkanes are saturated cyclic hydrocarbons
 Have the general formula (CnH2n)
Naming Cycloalkanes
1) Find the parent. # of carbons in the ring.
2) Number the substituents to get the lowest number set possible.
Cycloalkanes as substituents
 If the number of carbon atoms in the largest
acyclic substituent is greater than the number of
carbons in the ring, the cycloalkane is a
substituent.
sec-butylcyclohexane
4-cyclohexylheptane
4.2 Cis-Trans Isomerism in
Cycloalkanes
 Cycloalkanes are less flexible than open-chain
alkanes
 Much less conformational freedom in
cycloalkanes
Cis-Trans Isomerism in
Cycloalkanes (Continued)

-
Because of their cyclic structure, cycloalkanes have 2 faces as
viewed edge-on
“top” face
“bottom” face
Therefore, stereoisomerism (Same formula, same arrangement,
different 3D orientation) is possible in substituted cycloalkanes
There are two different 1,2-dimethylcyclopropane isomers
3.1 Functional Groups
 Functional group - collection of atoms at a site that have a
characteristic behavior in all molecules where it occurs
 The group reacts in a typical way, generally independent of
the rest of the molecule
 For example, the double bonds in simple and complex
alkenes react with bromine in the same way
Functional Groups with Multiple
Carbon–Carbon Bonds
 Alkenes have a C-C double bond
 Alkynes have a C-C triple bond
 Arenes have special bonds that are represented as
alternating single and double C-C bonds in a sixmembered ring
Functional Groups with Carbon Singly
Bonded to an Electronegative Atom
Functional Groups with a Carbon–Oxygen
Double Bond (Carbonyl Groups)
Survey of Functional Groups
Survey of Functional Groups
Alkenes




Alkynes contain a double bond.
General formula is CnH2n.
Each double bond has 1 degree of unsaturation.
Geometry is triangular.
7.3 Naming Alkenes
1.
2.
3.
4.
5.
6.
7.
8.
Name the longest chain that contains the double bond or double
bonds.
Replace the –ane from the alkane name with –ene.
Number this longest chain so the C=C bond or bonds has/have the
lowest number.
The locant(s), i.e., positional identifiers, for the double bond is
assigned to the first C of each C=C bond.
Name the attached functional groups.
Combine the names of the attached groups and longest chain, the
same as you would with alkanes.
For multiple double bonds, indicate the locations of all multiple bonds,
drop only the –ne from the alkane, and attach numeric prefixes
indicating the number of double bonds (-diene, -triene, -tetraene).
For alkenes with a single double bond, indicate cis- or trans- when
applicable. If alkenes have more than 1 double bond, use E, Z
nomenclature.
7.3 Naming Alkenes
 Name the parent hydrocarbon
 Number the carbons in chain so that double bond carbons
have lowest possible numbers
Naming Alkenes (Continued)
Br
(2E)-but-2-ene
2-methylpent-2-ene
(3Z)-3-methylhex-3-ene
(3E)-3-bromo-4-methylhex-3-ene
Cl
I
(3Z)-3,4,5-trimethylhept-3-ene
(4Z)-3,4,7-trimethylocta-1,4,6-triene
H
Cl
4-methylcyclohexene
5-chlorocyclopenta-1,3-diene
(2Z,4E)-1-chloro-5-iodo-2,4-dimethylhexa-2,4diene
Br
(5S)-5-bromocyclohexa-1,3-diene
Many Alkenes Are Known by
Common Names
Cis-Trans Isomerism in
Alkenes
 Rotation of  bond is prohibitive
 This prevents rotation about a carbon-carbon double
bond (unlike a carbon-carbon single bond).
 Creates possible alternative structures
Cis-Trans Isomerism in Alkenes
(Continued)
 the presence of a carbon-carbon double bond can create two
possible structures
 cis isomer - two similar groups on same side of the double
bond
 trans isomer - similar groups on opposite sides
 Each carbon must have two different groups for these isomers
to occur
Cis-Trans Isomerism in Alkenes
(Continued)
 Cis-Trans Isomerization requires that end groups differ
in pairs
 Bottom pair cannot be superposed without breaking
C=C
7.5 Alkene Stereochemistry and the E,Z
Designation
 Cis-Trans naming system discussed thus far only
works with disubstituted alkenes
 Tri- and Tetra substituted double bonds require
more general method
 Method referred to as the E,Z system
Alkene Stereochemistry and the E,Z
Designation (Continued): E,Z Stereochemical
Nomenclature
 Priority rules of
Cahn, Ingold, and
Prelog
 Compare where
higher priority groups
are with respect to
bond and designate
as prefix
 E -entgegen,
opposite sides
 Z - zusammen,
together on the same
side
Alkene Stereochemistry and the E,Z
Designation (Continued): Cahn-Ingold-Prelog
Rules
RULE 1
 Must rank atoms that are connected at comparison
point
 Higher atomic number gets higher priority
 Br > Cl > S > P > O > N > C > H
Alkene Stereochemistry and the E,Z
Designation (Continued): Cahn-Ingold-Prelog
Rules
RULE 2
 If atomic numbers are the same, compare at next connection
point at same distance
 Compare until something has higher atomic number
 Do not combine – always compare
Alkene Stereochemistry and the E,Z
Designation (Continued): Cahn-Ingold-Prelog
Rules
RULE 3
 Multiple-bonded atoms are equivalent to the same number of
single-bonded atoms
 Substituent is drawn with connections shown and no double or
triple bonds
 Added atoms are valued with 0 ligands themselves
Alkynes




Alkynes contain a triple bond.
General formula is CnH2n–2.
Each triple bond has 2 degrees of unsaturation
Geometry is linear.
H3C C C CH2
CH3
9.1 Naming Alkynes








Name of the compound ends in -yne.
Longest chain chosen for root name must include both C atoms of triple bond.
The root chain must be numbered from the end nearest a triple bond C atom.
 If the triple bond is in the center of the chain, the nearest substituent rule is
used to determine the end where numbering starts.
The smaller of the 2 numbers designating C atoms of triple bond is used as
the triple bond locator.
If several multiple bonds are present, each must be assigned a locator
number. Double bonds precede triple bonds in the IUPAC name, but the chain
is numbered from the end nearest a multiple bond, regardless of its nature.
The name will then have multiplier prefix (e.g., diyne, triyne, etc.)
If double and triple bonds are tied numerically, double bond takes precedence.
Because the triple bond is linear, it can only be accommodated in rings larger
than 10 carbons. In simple cycloalkynes the triple bond carbons are assigned
ring locations #1 and #2. Which of the two is #1 may be determined by the
nearest substituent rule.
Substituent groups containing triple bonds are:
HC≡C– Ethynyl group
Examples: Naming Alkynes
H3C
CH3
but-2-yne
H3C
CH3
H3C
CH3
H3C
pent-2-yne
CH3
hex-3-yne
CH3
HC
Br
2-bromohex-3-yne
Br
5-bromohexa-1,3-diyne
Examples: Naming Alkynes
Cl
Examples: Naming Alkynes
hepta-1,5-diyne
hept-1-en-5-yne
(3E)-hepta-1,3-dien-5-yne
Cl
(5E)-hept-5-en-1-yne
5-chlorohept-1-en-6-yne
15.1 Naming Aromatic
Compounds
 Many common names (toluene = methylbenzene; aniline
= aminobenzene)
 Monosubstituted benzenes systematic names as
hydrocarbons with –benzene


C6H5Br = bromobenzene
C6H5NO2 = nitrobenzene, and C6H5CH2CH2CH3 is
propylbenzene
Aromatics






6 C ring structures with alternating double bonds (benzene).
Everything that is not aromatic, is aliphatic (alkanes, alkenes,
alkynes).
Early problem chemists found was that benzene was not reactive
(recall that alkenes are reactive due to double bond).
Kekule proposed that double bonds alternated between 2 equivalent
structures
electrons move around a conjugated pi bond system of rings
Stabilizes structure and makes it less reactive.
Naming Benzene Derivatives
1. For single replacement (H some FG), cmpd named
as a benzene derivative.
CH3
O
+
O
-
N
propylbenzene
H3C
nitrobenzene
CH3
isopropylbenzene
OH
CH3
methylbenzene
O
hydroxybenzene
OH
carboxybenzene
Naming Benzene Derivatives
(Continued)
Some common names are IUPAC-accepted and used
preferentially.
Naming Benzene Derivatives
(Continued)
 With only 2 groups on benzene ring, can use o, m, p
(ortho, meta, para) nomenclature.
CH3
CH3
CH3
CH3
CH3
CH3
oO
H3C
+
N
O
-
m-
pNH2
Cl
Cl
CH3
o-nitrotoluene
m-dichlorobenzene p-methylaniline
p-aminotoluene
Naming Benzenes with More Than
Two Substituents
 Choose numbers to get lowest possible values
 List substituents alphabetically with hyphenated numbers
 Common names, such as “toluene” can serve as root
name (as in TNT)
The Phenyl Group
 When a benzene ring is a substituent, the term
phenyl is used (for C6H5 ?)
 You may also see “Ph” or “f” in place of “C6H5”
 “Benzyl” refers to “C6H5CH2 ?”
Benzene as a Phenyl group
• The benzene ring can also be an attached substituent group.
H3C
CH3
4-phenylheptane
1,1-diphenylcyclobutane
Alcohols and Phenols



Alcohols contain an OH group connected to a saturated C (sp3)
They are important solvents and synthesis intermediates
Phenols contain an OH group connected to a carbon in a benzene
ring
 Methanol, CH3OH, called methyl alcohol, is a common solvent, a fuel
additive, produced in large quantities
 Ethanol, CH3CH2OH, called ethyl alcohol, is a solvent, fuel, beverage
 OH groups bonded to vinylic sp2-hybridized carbons are called enols
Classifications of Alcohols
 General classifications of alcohols based on
substitution on C to which OH is attached
 Methyl (C has 3 H’s), Primary (1°) (C has two
H’s, one R), secondary (2°) (C has one H, two
R’s), tertiary (3°) (C has no H, 3 R’s)
17.1 Naming of Alcohols

Step 1: Identify longest chain that includes the (-OH) group(s).



If 1 alcohol, drop –e from hydrocarbon name, and replace with –ol.
If multiple alcohols, do NOT drop –e, but add –ol suffix, modified with
numeric prefix (diol, triol, tetraol, etc.).
Step 2: Number this parent chain to give lowest number to carbon with
attached (-OH) group.

Assign positional identifier(s) of (-OH) group(s).

Step 3: Locate and name all branches attached to parent chain.
 Step 4: Include names of all branches (still in alphabetical order) in
prefix of compound name. Include location of (-OH) group.
1
5
H3C
2
4
3
OH
H3C
2 3
CH3
2-ethyl-1-pentanol
HO
1
4
OH
2-methyl-1,4-butanediol
Naming of Alcohols
HO
CH3
H3C
OH
CH3
Br
HO
H3C
H3C
OH
CH3
OH
CH3
OH
H3C
H3C
OH
OH
H3C
CH3
HO
CH3
H3C
H3C
OH
CH3
H3C
CH3
OH
OH
OH
CH3
Naming of Alcohols
HO
CH3
H3C
OH
CH3
Br
HO
H3C
H3C
OH
CH3
2,2,4-trimethyl-3-hexanol
OH
CH3
5-bromo-3-ethyl-1-pentanol
OH
H3C
H3C
OH
OH
1,2,4-hexanetriol
H3C
CH3
HO
CH3
3-butyl-2,4-hexanediol
H3C
H3C
2,2-dimethylcyclopentanol
H3C
OH
CH3
3-methyl-3-pentanol
CH3
OH
OH
OH
CH3
1,2-cyclohexanediol
2-isopropyl-1-methylcyclopropanol
3-phenyl-1-propanol
Ethers and Their Relatives

An ether has two organic groups (alkyl, aryl, or vinyl) bonded to the
same oxygen atom, R–O–R
 Diethyl ether is used industrially as a solvent
 Tetrahydrofuran (THF) is a solvent that is a cyclic ether
 Thiols (R–S–H) and sulfides (R–S–R) are sulfur (for oxygen)
analogues of alcohols and ethers
18.1 Naming Ethers

Common Names
1.
2.

Name the two groups attached to the oxygen then add the word ether
If both groups the same, can be named with prefix di-.
IUPAC Names


O-R group is alkoxy.
The –yl ending of smaller R group is replaced by –oxy.
O
CH3
H3C
butyl methyl ether
1-methoxybutane
H3C
H3C
O
p-methoxytoluene
CH3
CH3
Cl
CH3
H3C
O
dipropyl ether
1-propoxypropane
CH3
isopropyl propyl ether
1-isopropoxypropane
ethyl propyl ether
1-ethoxypropane
H3C
CH3
O
CH3
CH3
O
H3C
CH3
O
CH3
2-ethoxy-3,4dimethylhexane
H3C
O
CH3
CH3
2-chloro-1-isopropoxypropane
Naming Thiols
Thiols: Sulfur analogs of alcohols (-SH instead of –OH)
 Chemically- similar (i.e., form similar compounds)
 More volatile (lower BP) than alcohols but less water-soluble
 Thiols stink!






This is how skunks defend themselves
Chopped onions emit propanethiol
Thiols found in garlic
Ethanethiol added to natural gas (methane) so you can smell a leak
IUPAC Names for simple thiols


The –SH group is a sulfhydryl group.
Follow the same steps for naming as you do for alcohols, but do not modify
alkane ending; instead add –thiol to end of parent.
SH
H3C
H3C
butanethiol
SH
SH
CH3
2-butanethiol
H3C
CH3
CH3
2-methyl-3-hexanethiol
19.1 Naming Aldehydes and
Ketones
Aldehyde: Carbonyl group with one or two H
attached.
 Named by replacing –e with –al (IUPAC).
H
 The aldehyde C is always numbered as 1.
Ketone: Carbonyl group with two
C attached.
• Named by replacing –e with –
one (IUPAC).
• Numbered from end closest to
carbonyl group
O
R
R
O
O
H
R
H
Naming Aldehydes
Aldehydes are named by replacing the terminal –e of the
corresponding alkane name with –al
 The parent chain must contain the –CHO group
 The –CHO carbon is numbered as C1
 If the –CHO group is attached to a ring, use the suffix
carbaldehyde
Naming Aldehydes
O
H3C
O
H
pentanal
O
Cl
H3C
H
H
5-chloropentanal
CH3
H
CH3
O
2-ethylbutanal
O
H
Cl
Cl
m-chloro-benzaldehyde
5-chloro-2-methylbenzaldehyde
CH3
O
H
CH3
H3C
O
H
CH3
3,4-dimethylhexanal
O
CH3
5-methoxy-2-methylbenzaldehyde
Naming Ketones
 Replace the terminal -e of the alkane name with –one
 Parent chain is the longest one that contains the ketone
group

Numbering begins at the end nearer the carbonyl carbon
Naming Ketones
O
O
O
H3C
Cl
CH3
Cl
CH3
2-pentanone
CH3
1-chloro-3-pentanone
5-chloro-2-pentanone
O
F
O
CH3
H3C
CH3
4-ethylcyclohexanone
CH3
2-fluoro-5-methyl-4-octanone
Naming Ketones
O
O
O
O
Cl
butan-2-one
3,5-dimethylheptan-4-one
3-chloro-5-ethylheptan-4-one
O
O
O
but-3-en-2-one
OH
O
4-hydroxybutan-2-one
octane-2,7-dione
3-methylcyclopentanone
Cl
O
O
O
Cl
Br
7-bromo-3-chloro-4-methylcyclooctanone
cyclohex-2-en-1-one
3-chloro-5-ethyloct-7-en-1-yn-4-one
Ketones/Aldehydes as Minor
FGs, Benzaldehydes
O
H
O
O
O
O
OH
H
O
O
O
3-oxopentanal
3,4-dioxopentanal
3,4-dioxopentanoic acid
O
O
O
Cl
H
H
OH
H
O
benzaldehyde
O
H
O
3-chlorobenzaldehyde
O
O
H
3-oxopropanoic acid
O
2-formylbenzoic acid
O
O
H
methyl 3-oxopropanoate
O
O
methyl 3-oxobutanoate
If C=O is lower priority functional group
• Ketone/aldehyde is oxo group
• Aldehyde is formyl group (on benzene)
• Aldehyde is higher priority than ketone
Functional Group Priority
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Carboxylic Acids (3 O bonds, 1 OH)
Esters (3 O bonds, 1 OR)
Aldehydes (2 O bonds, 1H)
Ketones (2 O bonds)
Alcohols (1 O bond, 1 OH)
Amines
Alkenes, Alkynes
O
OH
Alkanes
Ethers
OH
Halides
2-ethyl-4-hydroxybutanoic acid
The parent will be determined based on the highest priority functional group.
20.1 Naming Carboxylic Acids




Identify the longest C chain including the carboxyl group.
Number the parent chain so that carboxyl C has lowest number.
So for monocarboxylic acids, this will be 1, and does not need to be
numbered in naming.
Drop final –e (or –ene from benzene) from parent chain and replace with –
oic acid.
Alternative Names
 Compounds with –CO2H bonded to a ring are named
using the suffix -carboxylic acid
 The CO2H carbon is not itself numbered in this system
 Use common names for formic acid (HCOOH) and
acetic acid (CH3COOH) – see Table 20.1
Nitriles, RCN
 Closely related to carboxylic acids named by adding -
nitrile as a suffix to the alkane name, with the nitrile
carbon numbered C1
 Complex nitriles are acids; named as derivatives of
carboxylic acids.

Replace -ic acid or -oic acid ending with -onitrile
Naming Esters
 Esters may have common or IUPAC names
 The first word of the name of an ester is the name of alkyl or aromatic group (R)
 Change the –ic acid ending of the acid name to –ate (like naming carboxylic acid
salts)
 Parent contains the –COO group
O
O
O
CH3
O
O
O
CH3
CH3
CH3
methyl ethanoate
phenyl butanoate
ethyl benzoate
O
H
CH3
O
O
O
CH3
CH3
isopropyl
methanoate
methyl benzoate
Naming Amides, RCONH2
 With unsubstituted NH2 group. replace -oic acid or -ic
acid with -amide, or by replacing the -carboxylic acid
ending with –carboxamide
 If the N is further substituted, identify the substituent
groups (preceded by “N”) and then the parent amide
Naming Amides
O
H3C
CH3
N
O
H3C
CH3
N,N-dimethylethanamide
CH3
N
H
CH3
N-isobutylmethylbutanamide
O
O
N
NH
CH3
N-ethyl-Nphenylbenzamide
CH3
CH3
N,2-dimethylbenzamide
IUPAC Names – Simple
Amines
 For simple amines, the suffix -amine is added to
the name of the alkyl substituent
IUPAC Names – “-amine”
Suffix
Replace –e in alkane with –amine.
Number position of amino group lowest on parent chain.
If substituent on nitrogen, prefixed with N.



H3C
NH2
H3C
CH3
NH2
3-Pentanamine
H3C
H3C
H3C
3-Methyl-1-butanamine
CH3
NH
H3C
HN
CH3
N
CH3
CH3
NH2
CH3
2-Hexanamine
N-Methyl-2-butanamine
H3C
N-Methyl-2-hexanamine
CH3
N,N-Dimethyl-2-hexanamine
NH2
H3C
CH3
N
H3C
H3C
CH3
CH3
N-Ethyl-N-methyl-2-hexanamine
NH2
H3C
CH3
NH2
2,5-hexanediamine
cyclohexylamine
IUPAC Names – Amines with
More Than One Functional Group
 Consider the –NH2 as an amino substituent on
the parent molecule
IUPAC Names – Multiple Alkyl
Groups
 Symmetrical secondary and tertiary amines are
named by adding the prefix di- or tri- to the alkyl
group
IUPAC Names – Multiple,
Different Alkyl Groups
 Named as N-substituted primary amines
 Largest alkyl group is the parent name, and other
alkyl groups are considered N-substituents
Common Names of Heterocyclic
Amines
 If the nitrogen atom occurs as part of a ring, the
compound is designated as being heterocyclic
 Each ring system has its own parent name