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Nomenclature
Alkanes:
1.
Determine the number of carbons in the longest continuous
chain. This is the parent hydrocarbon (“last name”).
As this chain is six carbons long, the parent name is: hexane
2.
Any groups that are not part of the chain continuous chain are
substituents. Number the chain in the direction that gives the
substituent the lower number. Number are used for systematic
names only (never for common names).
a. Name: 2 3 - dimethylhexane
3.
Substituents are listed in alphabetical order. A number and word
are separated by a hyphen: numbers are separated by commas.
Prefixes like di, tri and tetra are ignored when alphabetizing.
a. Name: 2 , 2 – dimethyl – 4 – propyloctane
b. If the substituent is a branched chain then you will need to use
further specialized naming.
i. Name: 2,4 – dimethyl – 4 – (2 – methylpropyl)octane
4.
Only if the same set of numbers is obtained in both directions
does the first group cited get the lower number.
a. Name:
3 – ethyl – 4 – methylhexane
Regardless of the direction numbered, the substituents are on
the 3 and 4 carbon of the parent chain. In this case, take a
look at the substituents. In this example we have ethyl and
methyl. Because ethyl comes first (alphabetically) we will
preferentially give it the lower number.
5.
In the case of two hydrocarbon chains with the same number of
carbons, choose the parent to be one with more substituents.
a. Name:
5 – butyl – 3, 4, 6 – trimethylnonane
This means that the parent chain is:
6.
Give the systematic name for the following:
a. Name:
4 – ( 1,1 – dimethylethyl)octane
b. Name:
2,2 – dimethyl – 4 – propylheptane
c. Name:
3,3 – diethyl – 4 – methyl – 5 – propyloctane
CH3CH2C(CH2CH3)2CH(CH3)CH(CH2CH2CH3)2
Cycloalkanes
1.
In cycloalkanes with an attached alkyl substituent, the ring is the
parent hydrocarbon, unless the substituent has more carbon
atoms than in the ring. If there is only one substituent on a ring,
do not give that substituent a number.
a. Name:
ethylcyclobutane
2.
If the ring has two substituents they are cited in alphabetical
order and the number one position is given to the substituent
cited first.
a. Name:
1 – ethyl – 2 – methylcyclopentane
In this case the numbering is the same regardless of direction
that you count the chain. So we have the flexibility to given
the lower number preference to the substituents that is listed
first.
3.
If there is more than two substituents, the substituent given the
number one is the one that results in a second substituent getting
as low a number as possible. If two substituents have the same
low number, the ring is numbered in the direction that gives the
third substituent the lowest number possible.
a. Name:
4 – ethyl – 1,2 – dimethylcyclohexane
In this case we are more concerned with achieving lowest
possible numbers. So the fact the ethyl is listed first does not
factor into the numbering scheme.
4.
Give the systematic name for the following
a. Name:
2 – cyclopropylpentane
H3C
b. Name:
CH3
1 – ethyl – 3 – (2 – methylpropyl)cyclohexane
CH3
H3C
CH3
Alkyl Halides
1.
The common name s of the alkyl halides consist of the name of
the alkyl group, followed by the name of the halogen – with the
“ine” ending of the halogen name replaced with “ide”.
2.
In the systematic naming, the alkyl halides are named as
substituent alkanes. The prefixes for the halogens end with “o”
(fluoro, chloro, bromo, iodo).
3.
What is a primary, secondary and tertiary alkyl halide?
4.
Give the common and systematic names for the following and
indicate whether it is a primary, secondary or tertiary alkyl halide.
a. Common Name:
IUPAC:
sec – butyl chloride
2 – chlorobutane
secondary
H3C
CH3
Cl
b. Common Name:
IUPAC:
cyclohexyl bromide
bromocyclohexane
secondary
Br
c. Common Name:
IUPAC:
isohexyl chloride
1 – chloro – 4 – methylpentane
primary
CH3
H3C
Cl
Ethers
1.
The common name of an ether consists of the names of the two
alkyl substituents (in alphabetical order), followed by the word
“ether”.
2.
In the systematic scheme an ether is named as an alkane with an
RO substituents. The substituents are named by replacing the “yl”
ending in the name of the alkyl substituent with “oxy”. The
substituent group is the shorter of the two carbon chains.
3.
Give the systematic and common names (if there is one) for the
following:
a. Common Name:
IUPAC:
ethyl methyl ether
methoxyethane
H3C
O
CH3
b. Common Name:
IUPAC:
butyl propyl ether
1 – propoxybutane
H3C
O
CH3
c. Common Name:
IUPAC:
isopentyl isopropyl ether
3 – methyl – 1 – (1 – methylethoxy)butane
CH3
H3C
O
CH3
CH3
d. Common Name:
IUPAC:
No Common Name
2 – (1 – methylethoxy)pentane
CH3
H3C
CH3
O
CH3
Alcohols
1.
The common name for an alcohol consists of the name of the alkyl
group to which the OH group is attached, followed by the word
“alcohol”.
2.
The systematic name of an alcohol is obtained by replacing the
“e” at the end of the name of the parent hydrocarbon with the
suffix “ol”.
3.
The parent hydrocarbon is the longest continuous chain
containing the functional group.
a. Name:
4.
The parent hydrocarbon is numbered in the direction that gives
the functional group the lowest possible number.
a. Name:
5.
1 – pentanol
3 – hexanol
If there is a functional group suffix and a substituent, the
functional group suffix gets the lowest possible number.
a. Name:
4 - methylcyclohexanol
It is not necessary to include the “1” for the alcohol position.
Because functional groups take priority when naming it is
assumed that it is in the first position.
6.
If counting in either direction gives the same number for the
functional group suffix, the chain is numbered in the direction
that gives a substituent the lowest possible number.
a. Name:
7.
2,5 – dimethyl – 4 – heptanol
If there is more than one OH functional group use prefixes to
indicate the number.
a. Name: 2 , 4 – hexanediol
8.
What is a primary, secondary and tertiary alcohol?
9.
Give the systematic name for the following and indicate whether
it is primary, secondary or tertiary.
a. 5 – chloro – 2 – methyl – 2 – pentanol
tertiary
HO
CH3
H3C
Cl
b. 4 – bromo – 3 – ethylcyclohexanol
secondary
Br
H3C
OH
c. 2, 3 – dimethyl – 1 – butanol
primary
CH3
H3C
H3C
OH
Amines
1.
The common name of an amine consists of the names of the alkyl
groups bonded to the nitrogen, in alphabetical order, followed by
“amine”. (Note that the entire name is written as one word)
2.
For the systematic naming, use the suffix “amine” to denote the
amine functional group. The “e” at the end of the name of the
parent hydrocarbon is replaced by “amine”. A number identifies
the carbon to which the nitrogen is attached. The number can
appear before the name of the parent hydrocarbon (the longest
carbon continuous carbon chain attached to the amine group) or
before “amine”.
a. Name:
3.
The name of any alkyl group bonded to the nitrogen is preceded
by an “N” to indicate that the group is bonded to a nitrogen
rather than a carbon.
a. Name:
4.
1 - hexanamine
N, N – diethyl – 1 – propanamine
The substituents – regardless of whether they are attached to the
nitrogen or to the parent hydrocarbon – are listed in alphabetical
order. Each assigned either a number or “N” denoting its
location.
a. Name
N – (2 – methylpropyl) – 2 - butanamine
5.
The chain is numbered in the direction that gives the functional
group the lowest number.
a. Name:
N – ethyl – 3 – methylcyclopentanamine
6.
What is a primary, secondary and tertiary amine?
7.
Give the common (if there is one) and systematic name of the
following. Also indicate whether it is a primary, secondary or
tertiary amine.
a. Cyclohexanamine
primary
NH2
b. N, N – dimethyl – 3 - pentanamine
tertiary
H3C
H3C
N
CH3
CH3
c. N – ethyl – N – methylcyclohexanamine
tertiary
CH3
N
CH3
d. 5 – methyl – 1 – hexanamine
primary
CH3
H3C
NH2