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Introduction:
Organic compounds play
materials like clothing, fuels, polymers, and dyes. Organic chemistry is around two hundred
years old. The formation of acetic acid by Kolbe method showed that organic compounds
could also be prepared from inorganic
Organic chemistry is the branch of s
reactions, and uses of organic compounds.
Hydrocarbons are those compounds in which
hydrogen atoms.
All hydrocarbons are organic compounds but not all organic compounds are
hydrocarbons.
All carbon compounds except for a few inorganic carbon compounds are organic.
Inorganic carbon compounds include the oxides of carbon, the bicarbonates, and carbonates
of metal ions, metal cyanides, and a few others.
Nomenclature of Organic Compounds:
There are huge numbers of organic compounds are known. One might think that the
study of organic chemistry is very difficult. However it is not so because organic compounds
are classified into the various families on the basis of their propert
Classifications of Organic compounds are divided into various classes as follows.
1. Acyclic Compounds: Compounds in which all the carbon atoms are linked to one another
to form open chains(straight chain) are called acyclic, open chain or aliphat
saturated or unsaturated. For example,
Examples: -
1 CH4
2 CH3OH
3 CH2=CH-CH=CH
2. Cyclic compounds: Cyclic compounds which is made up of only one type of atom, the
compound is known as homo-cyclic
the compound is known as heterocyclic
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ORGANIC CHEMISTRY
Organic compounds play a vital role on this earth. Organic chemicals appear in
like clothing, fuels, polymers, and dyes. Organic chemistry is around two hundred
years old. The formation of acetic acid by Kolbe method showed that organic compounds
norganic-compounds.
Organic chemistry is the branch of science in which we study the properties,
reactions, and uses of organic compounds.
Hydrocarbons are those compounds in which a carbon atom is directly attached to
All hydrocarbons are organic compounds but not all organic compounds are
All carbon compounds except for a few inorganic carbon compounds are organic.
Inorganic carbon compounds include the oxides of carbon, the bicarbonates, and carbonates
of metal ions, metal cyanides, and a few others.
Compounds:
There are huge numbers of organic compounds are known. One might think that the
study of organic chemistry is very difficult. However it is not so because organic compounds
are classified into the various families on the basis of their properties.
Classifications of Organic compounds are divided into various classes as follows.
Compounds in which all the carbon atoms are linked to one another
to form open chains(straight chain) are called acyclic, open chain or aliphatic. These may be
saturated or unsaturated. For example,
Methane
Methyl alcohol
CH=CH2 Buta-1,3-diene
: Cyclic compounds which is made up of only one type of atom, the
cyclic and if the ring contains one heteroatom (N, S, and O),
heterocyclic compound.
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vital role on this earth. Organic chemicals appear in
like clothing, fuels, polymers, and dyes. Organic chemistry is around two hundred
years old. The formation of acetic acid by Kolbe method showed that organic compounds
cience in which we study the properties,
carbon atom is directly attached to
All hydrocarbons are organic compounds but not all organic compounds are
All carbon compounds except for a few inorganic carbon compounds are organic.
Inorganic carbon compounds include the oxides of carbon, the bicarbonates, and carbonates
There are huge numbers of organic compounds are known. One might think that the
study of organic chemistry is very difficult. However it is not so because organic compounds
Classifications of Organic compounds are divided into various classes as follows.
Compounds in which all the carbon atoms are linked to one another
ic. These may be
: Cyclic compounds which is made up of only one type of atom, the
and if the ring contains one heteroatom (N, S, and O),
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(a) Homocyclic compounds: these types of compounds contain ring, which are made up of
only one type of atoms. The organic compounds contain
known as carbo-cyclic compounds. They are divided into two parts
(i) Alicyclic compounds: Carbocyclic compounds which resemble aliphatic compounds in
their properties are called alicyclic compounds. These are the compound
carbon atoms are joined by the covalent bonds to form the ring structures.
(ii) Aromatic compounds: Organic compounds containing one or more fused or isolated
benzene rings (a six-member ring of carbon atoms with alternate single or
called aromatic compounds.
(b) Heterocyclic compounds: These are the compounds containing ring structure in which
one or more carbon atoms are replaced by hetro atoms (N, S, O etc) are known as
heterocyclic compounds. These are of two t
(i) Alicyclic Heterocyclic Compounds:
compounds in their properties are called alicyclic heterocyclic compounds.
(ii) Aromatic Heterocyclic Compounds:
compounds in most of their properties, are called aromatic heterocyclic compounds or non
benzenoid aromatic compounds.
Functional Group or Characteristic Groups:
determines the properties of the organic compound p
called a Functional group.
Organic compounds are classified into various families on the basis of their properties
most of the organic compound can be divided into two parts
(a) Reactive part called functional
(b) A Skelton of carbon and hydrogen atoms, which is called as
The properties of the compounds are generally controlled by functional groups.
For example- The properties of Ethyl alcohol (C
different though their alkyl radicals are same. The difference in properties due to the different
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these types of compounds contain ring, which are made up of
only one type of atoms. The organic compounds contain of only carbon atoms,
cyclic compounds. They are divided into two parts-
Carbocyclic compounds which resemble aliphatic compounds in
their properties are called alicyclic compounds. These are the compounds in which, the
carbon atoms are joined by the covalent bonds to form the ring structures.
: Organic compounds containing one or more fused or isolated
member ring of carbon atoms with alternate single or double bonds) are
: These are the compounds containing ring structure in which
one or more carbon atoms are replaced by hetro atoms (N, S, O etc) are known as
heterocyclic compounds. These are of two types:
(i) Alicyclic Heterocyclic Compounds: Heterocyclic compounds, which resemble aliphatic
compounds in their properties are called alicyclic heterocyclic compounds.
(ii) Aromatic Heterocyclic Compounds: heterocyclic compounds, which resemble aromatic
compounds in most of their properties, are called aromatic heterocyclic compounds or non
Functional Group or Characteristic Groups: An atom or group of atoms, which largely
determines the properties of the organic compound particularly the chemical properties, is
Organic compounds are classified into various families on the basis of their properties
most of the organic compound can be divided into two parts
functional group.
(b) A Skelton of carbon and hydrogen atoms, which is called as alkyl or aryl group.
The properties of the compounds are generally controlled by functional groups.
The properties of Ethyl alcohol (C2H5OH) and Ethylamine (C
different though their alkyl radicals are same. The difference in properties due to the different
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these types of compounds contain ring, which are made up of
of only carbon atoms, it is also
Carbocyclic compounds which resemble aliphatic compounds in
s in which, the
: Organic compounds containing one or more fused or isolated
double bonds) are
: These are the compounds containing ring structure in which
one or more carbon atoms are replaced by hetro atoms (N, S, O etc) are known as
Heterocyclic compounds, which resemble aliphatic
heterocyclic compounds, which resemble aromatic
compounds in most of their properties, are called aromatic heterocyclic compounds or non-
An atom or group of atoms, which largely
articularly the chemical properties, is
Organic compounds are classified into various families on the basis of their properties
alkyl or aryl group.
OH) and Ethylamine (C2H5NH2) are
different though their alkyl radicals are same. The difference in properties due to the different
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functional group attached to the alkyl chain. The
groups of alcohols and amines respectively.
Homologous Series: A series of closely related organic compounds, which can be
represented by a general formula, is called Homologous Series.
Characteristics of Homologous Series:
general formula.
S.No. IUPAC Name
1 Alkane
2 Alkene
3 Alkyne
4 Alkyl
• All members obey the same general formula.
• Every successive member differs by a methylene (
• They have similar chemical properties.
• Their physical properties such as melting point, boiling point, density, solubility etc shows
the regular gradation with the increase in molecular mass.
Nomenclature of Organic Compounds:
organic compounds are done.
(A) TRIVIAL SYSTEM: -
which they are obtained. Some compounds and their sources are given below:
Compound Name
NH2CONH2 Urea
HCOOH Formic Acid
CH3COOH Acetic acid
CH3 CH2 CH2COOH Butyric acid
(B) IUPAC SYSTEM: -
The nomenclature of the organic compounds is done by the systematic nomenclature system
given by IUPAC in 1950. The most widely used system is substitutive
substitutive name of an organic compound is based on its principal group and principal chain.
IUPAC: - “International Union of Pure and Applied Chemistry”. The IUPAC compounds
contains three parts namely-
Root Word- This is the basic unit, which indicate the carbon chain in the molecule structure.
It tells us the number of carbon atoms in the principle chain. Depending upon the numbers of
Carbon atoms the root words are as follows:
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functional group attached to the alkyl chain. The –OH and –NH2 groups are the functional
groups of alcohols and amines respectively.
A series of closely related organic compounds, which can be
represented by a general formula, is called Homologous Series.
Characteristics of Homologous Series: All member of a series can be represented by a
General Formula
CnH2n+2
CnH2n
CnH2n-2
CnH2n+1
obey the same general formula.
Every successive member differs by a methylene (-CH2-) group.
ve similar chemical properties.
Their physical properties such as melting point, boiling point, density, solubility etc shows
the regular gradation with the increase in molecular mass.
Nomenclature of Organic Compounds: - There are two methods by which naming of
In this system, compounds are named after the source from
which they are obtained. Some compounds and their sources are given below:
Name Source
Urea Urine
Formic Acid Formica (ant)
Acetic acid Acetum(sour)
Butyric acid Butyrum (butter)
The nomenclature of the organic compounds is done by the systematic nomenclature system
given by IUPAC in 1950. The most widely used system is substitutive nomenclature. The
substitutive name of an organic compound is based on its principal group and principal chain.
“International Union of Pure and Applied Chemistry”. The IUPAC compounds
unit, which indicate the carbon chain in the molecule structure.
It tells us the number of carbon atoms in the principle chain. Depending upon the numbers of
Carbon atoms the root words are as follows:
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groups are the functional
A series of closely related organic compounds, which can be
All member of a series can be represented by a
Their physical properties such as melting point, boiling point, density, solubility etc shows
There are two methods by which naming of
In this system, compounds are named after the source from
which they are obtained. Some compounds and their sources are given below:
Butyrum (butter)
The nomenclature of the organic compounds is done by the systematic nomenclature system
nomenclature. The
substitutive name of an organic compound is based on its principal group and principal chain.
“International Union of Pure and Applied Chemistry”. The IUPAC compounds
unit, which indicate the carbon chain in the molecule structure.
It tells us the number of carbon atoms in the principle chain. Depending upon the numbers of
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Suffix: Suffix is added indicating the saturated or
the functional group present in the molecule.
There are two types of Suffixes-
(i) Primary Suffix
(ii) Secondary Suffix
(i) Primary Suffix: - It tells the linkage between the carbon atoms.
(i) Secondary Suffix: It tells
compound. It is added to the name, after the primary suffix. Some common secondary
suffixes are given below.
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: Suffix is added indicating the saturated or unsaturated nature of the parent chain and
the functional group present in the molecule.
the linkage between the carbon atoms.
It tells the characteristic functional group present in the organic
compound. It is added to the name, after the primary suffix. Some common secondary
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unsaturated nature of the parent chain and
the characteristic functional group present in the organic
compound. It is added to the name, after the primary suffix. Some common secondary
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Note- When we are using these secondary suffixes, the carbon
is counted in the principle chain.
Prefixes: The prefix depends upon the carbon atom present in a parent chain.
Prefix indicates the substituent of other atoms or groups in place of hydrogen atom in the
main chain of carbon atoms. Most commonly used prefixes are alkyl groups and groups or
atoms, which are not regarded as principle functional groups. Some of
given below.
For Alcohol Group (OH) – e ----
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using these secondary suffixes, the carbon of the functional group (if any)
: The prefix depends upon the carbon atom present in a parent chain.
Prefix indicates the substituent of other atoms or groups in place of hydrogen atom in the
bon atoms. Most commonly used prefixes are alkyl groups and groups or
atoms, which are not regarded as principle functional groups. Some of these prefixes are
given below.
---- ol- Alkane in place of “e” - “ol” will come.
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of the functional group (if any)
: The prefix depends upon the carbon atom present in a parent chain.
Prefix indicates the substituent of other atoms or groups in place of hydrogen atom in the
bon atoms. Most commonly used prefixes are alkyl groups and groups or
these prefixes are
given below.
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For example-
For Ether Group (ROR) – Small group
Nomenclature of saturated branched
Position of Locants: A locant is numeral (1, 2, 3….) or a letter (o, m, p
the position of a substituents or a carbon
immediately before the part of the name of which they relate. For example, according to
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Small group-Oxi /Oxy and the remaining group-Alkane
branched hydrocarbons: -
is numeral (1, 2, 3….) or a letter (o, m, p- etc) used to locate
the position of a substituents or a carbon-carbon multiple bond. These locants are placed
immediately before the part of the name of which they relate. For example, according to
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Alkane
etc) used to locate
carbon multiple bond. These locants are placed
immediately before the part of the name of which they relate. For example, according to
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IUPAC names to the latest rules for Pent
correct.
Numerical Prefixes: Numerical prefixes are used to describe a multiplicity of identical
feature of a structure in chemical nomenclature. These are derived from Greek or
number names. Some common numerical prefixes are given below.
Numerical prefixes such as ‘bis’, ‘t
substituted substituents.
Bracket or Parenthesis: The brackets or Parenthesis
substituents after the numerical multiplicative prefix, if any.
Use of Hyphen: The use of hyphen, brackets, and numerical prefixes are illustrated in the
following examples;
-A hyphen separates a locant from the words of the name. F
Nomenclature of simple alkanes:
The names of first ten alkanes are given in the following tables:
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to the latest rules for Pent-2-ene, name like Pentene-2 or 2-Pentene are not
Numerical prefixes are used to describe a multiplicity of identical
feature of a structure in chemical nomenclature. These are derived from Greek or
number names. Some common numerical prefixes are given below.
ical prefixes such as ‘bis’, ‘tris’, tetrakis etc are used to indicate a multiplicity of a
The brackets or Parenthesis is used around prefixes defining
substituents after the numerical multiplicative prefix, if any.
The use of hyphen, brackets, and numerical prefixes are illustrated in the
A hyphen separates a locant from the words of the name. For example,
alkanes: -
The names of first ten alkanes are given in the following tables: -
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Pentene are not
Numerical prefixes are used to describe a multiplicity of identical
feature of a structure in chemical nomenclature. These are derived from Greek or Latin
used to indicate a multiplicity of a
round prefixes defining
The use of hyphen, brackets, and numerical prefixes are illustrated in the
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Nomenclature of branched alkanes:
1. Selection of Parent chain: -
Rule1: - Select the longest continuous chain of carbon atoms as a parental
All other carbon atoms, which are not included in this chain, are regarded as substituents and
denoted as prefixes.
Example: -
The given alkane is named as a
noted the longest chain may or may not be straight but it must be continuous.
Rule2: - If two and more than two longest chains are the present in the compound then the
chain having larger number of side chains will be principal chain.
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Nomenclature of branched alkanes: -
Select the longest continuous chain of carbon atoms as a parental (principal)
All other carbon atoms, which are not included in this chain, are regarded as substituents and
The given alkane is named as a derivative of the alkane representing the parent chain. It is
noted the longest chain may or may not be straight but it must be continuous.
If two and more than two longest chains are the present in the compound then the
mber of side chains will be principal chain.
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(principal) chain.
All other carbon atoms, which are not included in this chain, are regarded as substituents and
derivative of the alkane representing the parent chain. It is
If two and more than two longest chains are the present in the compound then the
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The chain (written in blue color) has side chains at 2, 3, 4, 5 carbon
(written in pink color) has side chains at 2, 3, 4 carbon atoms.
be the chain named in blue color.
Rule3: - Numbering of the Principle Chain: (Lowest Number of Rule):
carbon chain is numbered from the end nearest to the side chain or substituents
lowest no. to the carbon having the side chain.
The sums of the number assigned to the substituents are mini
the number indicating the substituents attached
In the above structure, if we start the numbering from left hand
comes at carbon number-5 while if we do the numbering from the right
substituted group comes at carbon
correct.
From the above figure, it is clear that in figure
Rule 4: - Numbering Same Substituents at Different Position
occurs more than one time in a
separated by commas and suitable n
the same. In case the same substituents occur twice on the same carbon atom, its positional
number is repeated twice with a comma in between.
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in blue color) has side chains at 2, 3, 4, 5 carbon atoms, while the chain
in pink color) has side chains at 2, 3, 4 carbon atoms. Therefore, longest chain will
be the chain named in blue color.
Numbering of the Principle Chain: (Lowest Number of Rule):
is numbered from the end nearest to the side chain or substituents
the side chain.
The sums of the number assigned to the substituents are mini-mum. Locant is used to denote
the number indicating the substituents attached.
In the above structure, if we start the numbering from left hand-side, then substituted group
5 while if we do the numbering from the right-hand side, then
substituted group comes at carbon-number-3. Therefore, Numbering from right hand side is
From the above figure, it is clear that in figure-2 the lowest set of locant is applicable.
Numbering Same Substituents at Different Position: When the same substituents
occurs more than one time in a parent chain, the positional number of each substituents is
separated by commas and suitable numerical prefixes such as di, tri, tetra, etc., are attached to
the same. In case the same substituents occur twice on the same carbon atom, its positional
number is repeated twice with a comma in between.
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while the chain
Therefore, longest chain will
Numbering of the Principle Chain: (Lowest Number of Rule): The selected
is numbered from the end nearest to the side chain or substituents to give the
Locant is used to denote
substituted group
hand side, then
3. Therefore, Numbering from right hand side is
lowest set of locant is applicable.
: When the same substituents
parent chain, the positional number of each substituents is
umerical prefixes such as di, tri, tetra, etc., are attached to
the same. In case the same substituents occur twice on the same carbon atom, its positional
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In this structure, methyl group is repeated thrice, so in the naming
used tri before methyl.
Rule5: - Alphabetic Order of Substituents:
- If more than one group attached to the carbon chain, they should be arranged
alphabetically.
- While deciding alphabetical order of simple substituents numerical affixes such as di,
tri, tetra – etc (if any) are not considered.
- When two or more identical substituents are present prefix
- The position of substituents is separated by commas
Example: -
Rule6: - Naming of Univalent Branched Chain Radicals: S
complex radicals are derived from the name of the alkane representing the longest chain. The
numbering should be done in the
Note: IUPAC has retained following semi systematic names for branched chain alkanes,
provided they are not substituted. However, these semi systematic names are not yet widely
accepted in IUPAC nomenclature.
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In this structure, methyl group is repeated thrice, so in the naming of the structure, we have
Alphabetic Order of Substituents:
If more than one group attached to the carbon chain, they should be arranged
While deciding alphabetical order of simple substituents numerical affixes such as di,
etc (if any) are not considered.
When two or more identical substituents are present prefix- di, tri, tetra- etc are used.
substituents is separated by commas
Naming of Univalent Branched Chain Radicals: Such substituted substituents or
complex radicals are derived from the name of the alkane representing the longest chain. The
the way that the carbon atom with free valence gets
IUPAC has retained following semi systematic names for branched chain alkanes,
provided they are not substituted. However, these semi systematic names are not yet widely
accepted in IUPAC nomenclature.
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structure, we have
If more than one group attached to the carbon chain, they should be arranged
While deciding alphabetical order of simple substituents numerical affixes such as di,
etc are used.
uch substituted substituents or
complex radicals are derived from the name of the alkane representing the longest chain. The
atom with free valence gets number 1.
IUPAC has retained following semi systematic names for branched chain alkanes,
provided they are not substituted. However, these semi systematic names are not yet widely
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Special Case of Nomenclature of Branched Chain Al
1. Deciding the Order of complex substituents:
the first letter of their complete names i.e., including the numerical affix (if any). This is clear
from the following compounds.
Here dimethylpropyl as a complex single substituents
such written before ‘e’ of ethyl.
In the case where the names of complex radicals are composed of identical words priority is
decided by considering the locants in the complex radicals. For
In second figure, numbering of the carbon atoms is done in wrong way. At carbon number
the attached group has substitute at carbon
has substitute (methyl) at carbon
lowest locant side.
2. Numbering of Different Substituents at Equivalent Positions
substituents are present at equivalent positions, the numbering of parent chain is done in such
a way that the substituent, which
For example-
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Special Case of Nomenclature of Branched Chain Alkanes:
Deciding the Order of complex substituents: Complex radicals are alphabetized under
the first letter of their complete names i.e., including the numerical affix (if any). This is clear
as a complex single substituents is alphabetized under‘d’
In the case where the names of complex radicals are composed of identical words priority is
decided by considering the locants in the complex radicals. For example,
In second figure, numbering of the carbon atoms is done in wrong way. At carbon number
the attached group has substitute at carbon-2, while at carbon-number-6, the attached group
has substitute (methyl) at carbon-1. We know that, numbering should be do
2. Numbering of Different Substituents at Equivalent Positions: When two different
substituents are present at equivalent positions, the numbering of parent chain is done in such
substituent, which comes first in the alphabetical order gets the lower number.
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Complex radicals are alphabetized under
the first letter of their complete names i.e., including the numerical affix (if any). This is clear
under‘d’ and as
In the case where the names of complex radicals are composed of identical words priority is
example,
In second figure, numbering of the carbon atoms is done in wrong way. At carbon number-5,
6, the attached group
1. We know that, numbering should be done from the
: When two different
substituents are present at equivalent positions, the numbering of parent chain is done in such
t in the alphabetical order gets the lower number.
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In this example, ethyl is written before methyl group because ‘E’ comes before
3. Deciding the Principal Chain When there are
When there are two or more chains
side chains as substituents should
In case if there are two or more chains of equal lengths have the same number of side chains,
then the chain whose side chain have the lowest numbered locants is selected as principal
For example,
Here the set of locant s 2, 4, 5 is lower than th
Example1: -Name the following compound using IUPAC substitutive nomenclature?
Solution: Principle chain contain 7 carbon atoms, hence it is substituted
heptane. The branches are at C-2 with methyl group and C
group.
According to IUPAC, rules if more than one group attached to
the carbon chain, they should be arranged
of the number assigned to the substituents are minimum.
Some important tips: -
1. Branching group are generally termed as substitu
alkyl substituent is derived by replacing ‘ane’ by ‘yl’.
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In this example, ethyl is written before methyl group because ‘E’ comes before ‘M’.
3. Deciding the Principal Chain When there are two or More Chains of Equal Lengths
r more chains of equal length, then the chain with greater number of
should be selected as principal chain for example,
two or more chains of equal lengths have the same number of side chains,
then the chain whose side chain have the lowest numbered locants is selected as principal
chain.
Here the set of locant s 2, 4, 5 is lower than the set 2, 4, 6
Name the following compound using IUPAC substitutive nomenclature?
Solution: Principle chain contain 7 carbon atoms, hence it is substituted
2 with methyl group and C-4 with ethyl
rules if more than one group attached to
the carbon chain, they should be arranged alphabetically, and the sum
of the number assigned to the substituents are minimum. It is 4-Ethyl-2-methyl-heptane.
group are generally termed as substituents. The name of an un
alkyl substituent is derived by replacing ‘ane’ by ‘yl’.
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‘M’.
or More Chains of Equal Lengths:
of equal length, then the chain with greater number of
two or more chains of equal lengths have the same number of side chains,
then the chain whose side chain have the lowest numbered locants is selected as principal
Name the following compound using IUPAC substitutive nomenclature?
heptane.
an un-branched
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2. The prefix n-(normal) refers to a straight chain alkyl group. If the name does not have
prefix ’n’, it is assumed that carb
3. The prefix-iso refers that a straight chain contains one methyl group at second carbon
from the opposite end.
4. The prefix-‘neo’ is used when a carbon is attached to three other carbons. It is used
mainly in pentane.
5. The prefix-‘s’ is used when a carbo
6. The prefix-‘t’ is used when a carbon is attached to three other carbons.
7. An acyclic bridge is named as a prefix derived from the hydrocarbon name by
changing the final ‘e’ to ‘o’. The
square brackets between the hydrocarbon prefix and the ending ‘
Compound structure
-CH2-
-CH2-CH2-
-CH=CH-
-CH=CH-CH2
-CH2-CH=CH-CH2-
-CH=CH-CH=CH-
Nomenclature of acyclic or heterogeneous bridge:
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(normal) refers to a straight chain alkyl group. If the name does not have
prefix ’n’, it is assumed that carbon atoms are in continuous chain.
iso refers that a straight chain contains one methyl group at second carbon
‘neo’ is used when a carbon is attached to three other carbons. It is used
‘s’ is used when a carbon is attached to two other carbons.
‘t’ is used when a carbon is attached to three other carbons.
An acyclic bridge is named as a prefix derived from the hydrocarbon name by
changing the final ‘e’ to ‘o’. The position of a double bond, if present is indicated in
square brackets between the hydrocarbon prefix and the ending ‘-eno’ or ‘
Name
Methano
Ethano
Etheno
Pro[1]eno
But[2]eno
Buta [1,3]dieno
Nomenclature of acyclic or heterogeneous bridge: -
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iso refers that a straight chain contains one methyl group at second carbon
‘neo’ is used when a carbon is attached to three other carbons. It is used
An acyclic bridge is named as a prefix derived from the hydrocarbon name by
position of a double bond, if present is indicated in
eno’ or ‘-dieno’, etc.
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Important: -
Common names that you should know are...
isopropyl = 1-methylethyl
isobutyl = 2-methylpropyl
sec-butyl = 1-methylpropyl
tert-butyl = 1,1-dimethylethyl
neo-pentyl = 2,2-dimethylpropyl
iso-pentyl = 3-methylbutyl
Example2: - Name the following compound using the IUPAC nomenclature.
(a) 4-propylheptane
(c) 2-methyl-3-propyl hexane
Answer: - (b)
The principal chain contains seven carbons; hence, it is substituted as
we have a branch of three carbons.
This branch is called isopropyl or 1
Therefore, name of the compound is
Example3: - Name the following compound using the IUPAC nomenclature.
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Common names that you should know are...
dimethylpropyl
Name the following compound using the IUPAC nomenclature.
(b) 4-(1-methylethyl) heptanes
propyl hexane (d) 4-propyl-5-methyl hexane
The principal chain contains seven carbons; hence, it is substituted as heptane. At carbon
we have a branch of three carbons.
This branch is called isopropyl or 1-methylethyl.
Therefore, name of the compound is 4-(1-methylethyl)heptane
Name the following compound using the IUPAC nomenclature.
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. At carbon-4,
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(a) 2,4-dimethyl-5-propylheptane
(b) 5-propyl-2,3-dimethylheptane
(c) 2,4-dimethyl-5-ethyloctane
(d) 5-ethyl-2,4-dimethyloctane
Answer: - (d)
The principal chain contains eight carbons; hence, it is substituted as octane. There are three
branches is attached to the principal chain. Two branches are methyl group and one branch is
ethyl group.
The name of the compound is 5-ethyl
(Ethyl will come before methyl)
Example4: - Name the following compound
Answer:-
(A) The IUPAC name of the compound is 3,3
(B) The name of the compound is 4
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propylheptane
dimethylheptane
ethyloctane
dimethyloctane
eight carbons; hence, it is substituted as octane. There are three
branches is attached to the principal chain. Two branches are methyl group and one branch is
ethyl-2, 4-dimethyloctane
Name the following compounds using the IUPAC nomenclature.
The IUPAC name of the compound is 3,3-dimethylhexane
The name of the compound is 4-(1,1-dimethylethyl)-heptane
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eight carbons; hence, it is substituted as octane. There are three
branches is attached to the principal chain. Two branches are methyl group and one branch is
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(C) The name of the compound is
Example5: - IUPAC name of neo
Answer: -
IUPAC name is 2,2-dimethylpropane
Example6: - Find out the primary, secondary, tertiary, and quaternary carbon in the
following compound.
Answer: -
Type of carbon
Primary
Secondary
Tertiary
Quaternary
Example7: - Write the IUPAC name of the following compound?
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The name of the compound is 5-ethyl-3-methyl-4-(1-methylethyl)-nonane
IUPAC name of neo-pentane is
dimethylpropane
Find out the primary, secondary, tertiary, and quaternary carbon in the
Position
1,9,11
2,3,5,8
6,7, 10
4
Write the IUPAC name of the following compound? (IIT-JEE-1990)
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Find out the primary, secondary, tertiary, and quaternary carbon in the
1990)
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Answer: -
IUPAC name is 5,6-diethyl-3-methyldecane
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methyldecane
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