Classification of organic compound, Nomenclature of alkane, alkene, alkyne, alcohol, alkyl halide, aldehyde, ketone, carboxylic acid and its derivatives, amines, ethers, polyfunctional groups and structural isomerism of organic compounds

1. Classification, nomenclature and
Isomerism of Organic Compounds
Mr. Mote Ganesh D.
Assistant Professor
ADCBP, Ashta

2. Classification
• Organic Compounds.
1. Aliphatic Compounds: e.g. ethane, ethyl alcohol, n-butyl amine
2. Saturated and unsaturated compounds:
a) ethane-saturated
b) ethylene- unsaturated
c) acetylene- unsaturated
3. Aromatic compounds: Benzene, Aniline, Naphthalene
4. Alicyclic compounds: Cyclopropane, Cyclobutane, cyclohexane
5. Heterocyclic Compounds: Pyrrole, Pyridine and Quinoline
2Mr. Mote G.D.

3. Classification
1. Aliphatic compounds: The compounds which contains open
chain of carbon atoms are called as aliphatic compounds
2. Saturated and Unsaturated Compounds:
a) The compounds which contains carbon carbon single bond
are known as saturated
b) The compounds which contains carbon carbon double and
triple bond are known as unsaturated
H3C CH3
ethane
CH3-CH2-OH
ethyl alcohol
CH3
H2
C NH2
ethyl amine
H3C CH3
ethane
H2C CH2
ethylene
HC CH
acetylene
3Mr. Mote G.D.

4. Classification
3. Aromatic compounds: The compounds that have structures and
chemical properties resembling with benzene are called as
Aromatic compounds
4. Alicyclic compounds: Cyclic compounds contain only carbon atoms
called as alicyclic compounds.
5. Heterocyclic compounds: Cyclic compounds in which contain
carbon and hetero atom known as heterocyclic compounds.
NH2
anilinebenzene
naphthalene
cyclopropane cyclobutane cyclopentane cyclohexane
N
H
O
N
pyrrole
oxirane
pyridine
4Mr. Mote G.D.

5. Functional groups: Functional group is the reactive part of an organic molecule
Sr. No Class of compounds example structure
1. Alkane Ethane
2. Alkene Ethylene
3. Alkyne Acetylene
4 Alcohol Ethyl alcohol
5 Ether Diethyl ether
6 Aldehyde formaldehyde
7 Ketone acetone
9 Carboxylic acid Acetic acid CH3COOH
10 Ester Mthyl acetate CH3COOCH3
11 Amine Ethyl amine CH3CH2NH2
12 Nitro compounds Nitro methane CH3NO2
13 Alkyl Halide Methyl chloride CH3Cl
14 Amide Formamide HCONH2
15 Thiol Ethanethiol CH3CH2SH
CH3 CH3
H2C CH2
HC CH
H3C C
H2
OH
H3C C
H2
O CH2 CH3
H C
O
H
H3C C
O
CH3
5Mr. Mote G.D.

6. Nomenclature of alkanes
Common system:
• the first four members of the series are called by their common names .i.e methane, ethane, propane, butane and higher
alkanes are derived from Greek prefixes that indicates the number of carbon atoms in the molecule. E.g. Pentane has five
carbons
• The prefix n- is used for those alkanes in which all carbons are in one continuous chain
• Prefix iso is used for those alkanes which have a methyl group attached to second last carbon atom of continuous chain.
• Prefix neo is used for those alkanes which have two methyl groups attached to the second last carbon atom
• Alkyl group is formed by removing one hydrogen from an alkane. The suffix of this group is –yl
• Non alkyl groups: F-Fluro, Cl- Chloro, Br- Bromo, I- Iodo, NO2- Nitro, NH2- Amino, OH- Hydroxy
CH3 CH2 CH3
n-propane
CH3 C
H
CH3
isobutane
CH3
CH3 C CH3
CH3
CH3
neo pentane
6Mr. Mote G.D.

7. Parent alkanes
Sr.No Name structure
1 Methane CH4
2 Ethane CH3-CH3
3 Propane CH3-CH2-CH3
4 Butane CH3-CH2-CH2-CH3
5 Pentane CH3-CH2-CH2-CH2-CH3
6 Hexane CH3-CH2-CH2-CH2-CH2-CH3
7 Heptane CH3-CH2-CH2-CH2-CH2-CH2-CH3
8 Octane CH3-CH2-CH2-CH2-CH2-CH2-CH2-CH3
9 Nonane CH3-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
10 Decane CH3-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
7Mr. Mote G.D.

8. IUPAC Nomenclature
Sr. No Functional group Prefix Suffix
1 Alkane alkyl -ane
2 Alkene - -ene
3 Alkyne - -yne
4 Carboxylic acid carboxyl -Oic acid
5 Acid Halide -yl halide -oyl halide
6 Acid Amide -amide -amide
7 Acid Anhydride -ic anhydride Oic anhydride
8 Ester - -ate
9 Aldehyde -oxo -al
10 Ketone -oxo -one
11 Alcohol -hydroxy -ol
12 Amine -amino -amine
13 -Cl, F, Br, I Fluoro, Chloro, Bromo, iodo -
14 NO2 -Nitro -
8Mr. Mote G.D.

9. Rules for IUPAC nomenclature
1. Find the longest continuous carbon chain.
2. Determine the root name for this parent chain.
3. Number the chain in the direction such that the position number
of the first substituent is the smaller number.
4. If the first substituents from either end have the same number,
then number so that the second substituent has the smaller
number
5. Determine the name and position number of each substituent.
6. Indicate the number of identical groups by the prefixes di, tri,
tetra, etc.
7. Place the position numbers and names of the substituent groups,
in alphabetical order, before the root name.
9Mr. Mote G.D.

10. IUPAC Nomenclature of alkanes
• The steps for alkanes= Prefix------Parent--------Suffix.
• Rules for nomenclature of alkanes
1. Name the longest chain- the longest continuous carbon
chain is chosen and given parent name.
2. Number the longest chain- the carbon atoms in longest
chain are numbered and numbering started from the end
where substituent is attached
3. Locate and name of substituent's- Each substituent is
named and position of each substituent is indicated by
number.
4. Combine the longest chain and substituent's- The
position and name of substituent are added to the name
of the longest chain and written as one word.
CH3 CH2
H
C CH3
CH3
butane
CH3 CH2
H
C CH3
CH3
1234
CH3 CH2
H
C CH3
CH3
1234
2-Methyl
CH3 CH2
H
C CH3
CH3
1234
2-Methylbutane
10Mr. Mote G.D.

11. IUPAC Nomenclature of alkanes
5. Indicate the number and position of substituent's-
If the same substituent is present two or more time in the molecule at that time
substituent is indicated by prefix di, tri, tetra, penta and location is indicated by
separate numbers
If two or more substituents are present, their names are alphabetized and added to
the parent alkane
H
C CH2
H
C CH3
CH3
H3C
CH3
2,4-dimethylpentane
CH3 C
H
Br
H
C CH3
Cl
2-bromo-3-chlorobutane
11Mr. Mote G.D.

12. Nomenclature of alkene
• Common system-
1. the common names of the first four members named by
changing –ane to –ylene.
2. The Greek letters are used to distinguish isomers having
double bond at the first and second carbon of the chain
CH2 C
H
CH3
Propylene
CH2 CH2
ethylene
CH3
H
C C
H
CH3
Β-Butylene
H2C
H
C CH2 CH3
α-Butylene
12Mr. Mote G.D.

13. IUPAC Nomenclature alkene
1. The IUPAC names of alkenes are derived from those of the corresponding alkanes
by changing the ending –ane to –ene.
2. Select the longest continuous carbon chain that contains the double bond and use
this as the parent compound.
3. Number this longest continuous chain so that the double bond has the lowest
possible number.
4. To indicate the position of the carbon- carbon double bond, add the number of
lower numbered carbon atom of carbon carbon double bond in front of the alkene
name.
5. Side chain and substituents are named as usual and their position is indicated by
number to show to which carbon atom they are attached.
6. When there are two or three double bonds in a molecule, the –ane is replaced by
–adiene and -atriene.
H2C
H
C CH2 CH3
1- butene
CH3
H
C C
H
CH3
2-butene
H2C C CH2 CH3
CH3
2-methyl-1-butene
H2C
H
C C
H
CH2
1,3 Butadiene
13Mr. Mote G.D.

14. Nomenclature of alkyne
• Common system: acetylene is the common name of for the first member of the
series.
• Derived system: Higher alkynes are regarded as alkyl derivatives of acetylene.
• IUPAC Nomenclature: The IUPAC names of alkynes are obtained by dropping the
ending –ane of parent alkanes and adding the suffux –yne.
HC CH
Acetylene
C C
Dimethylacetylene
CH3H3C
HC CH
ethyne
C C CH3H3C
2-butyne
14Mr. Mote G.D.

15. Nomenclature for alkyl halide
• Common system: in this system the alkyl group attached to the halogen atom is
named first alkane and then chloride, fluoride and bromide will come.
• Suffix for alkyl halides is –yl halide
CH2 ClH3C
ethyl chloride
CH3 Br
Methyl bromide
CH3 CH
CH3
Br
Isopropyl bromide
15Mr. Mote G.D.

16. Nomenclature for alkyl halide
IUPAC Nomenclature:
1. The longest continuous chain of carbon atoms is chosen as the parent. if parent chain has no branching alkyl group, the position of halogen atom is
given by a number that corresponds to the carbon atom to which it is attached. The carbon chain is numbered so that the carbon atom bearing the
halogen atom has the lowest number.
2. If the parent chain has branching alkyl group, number the chain from the end near to first substituent.
3. If the compound contains two or more halogen atoms of the same type, they are indicated with prefixes di-, tri-, etc.
4. If the compound contains different substituent's, they are numbered according to their positions on the chain and listed in alphabetical order.
CH3 CH2 CH
Cl
CH3
1
234
2-chlorobutane
CH3 CH CH
H2
C CH3
CH3
Cl
3-chloro-2-methylpentane
CH3 CH CH
H2
C CH3
Cl
Cl
2,3-dichloropentane
CH3 CH C
H2
CH CH3
Br CH3
2-bromo-4-methylpentane
Br
CH3
CH3
3-bromo-1,1-dimethylcyclopentane
16Mr. Mote G.D.

17. Nomenclature of alcohol
• Common system: in this system alcohols(R-OH) are named as
alkyl alcohol.
• IUPAC Nomenclature :
1. Select the longest continuous carbon chain containing the –OH group.
2. Change the name of the alkane corresponding to this chain by dropping the ending
–e and adding suffix –ol.
3. Number the chain so as to give the carbon carrying the –OH group, the lowest
possible number. The possition of -OH group is indicated by this number.
4. Indicate the positions of other substituents or multiple bonds by numbers.
5. When –OH is part of higher priority class of compound, it is named as hydroxy.
Priority of functional group: Acids>esters >aldehyde >ketone >alcohol >amine >alkene
>alkyene >alkane >ethers >Halides
CH3 OH
methyl alcohol
CH3 CH2 OH
ethyl alcohol
CH3 C
H
CH3
OH
Iso propyl alcohol
17Mr. Mote G.D.

18. IUPAC Nomenclature of alcohol
CH3 CH2
H
C CH2
OH
H2
C
H
C CH3
CH3
6-methylheptan-3-ol
CH3 OH
methanol
CH3 CH2 OH
ethanol CH3 C
H
CH3
OH
2-propanol
18Mr. Mote G.D.

19. Nomenclature of ethers
• Common system: The two alkyl groups attached to oxygen
are named in alphabetical order and word ether is added. If
the two alkyl groups are same (R-O-R), the prefix di- is used.
• IUPAC Nomenclature:
• ethers are named as alkoxy alkanes.
• The larger alkyl group is considered to be alkanes or parent.
• The name of the alkane is prefixed by the name of alkoxy
group and position number.
CH3 O CH2CH3
ethyl methyl ether
O CH2 CH3H2CH3C
diethyl ether
CH3 O CH2CH3
methoxyethane
O CH2 CH3H2CH3C
ethoxyethane
19Mr. Mote G.D.

20. Nomenclature of oxiranes
• Common system: usually they alkene epoxide because they
are made from alkenes.
• IUPAC Nomenclature: In this system ethylene oxide is called
as oxirane and epoxides are named as substituted oxiranes.
H2C CH2
O
ethylene oxide
(epoxy ethane)
H2C
H
C
O
CH3
Propylene oxide
(epoxy propane)
H2C
H
C
O
CH3
2-methyloxirane
H2C CH2
O
oxirane
H2C C
O
CH3
CH3
2,2-dimethyloxirane
20Mr. Mote G.D.

21. Nomenclature of aldehyde
• Common system: The name of simple aldehydes are derived
from the common names of corresponding carboxylic acid.
• The characteristic –ic acid ending in the common name of
carboxylic acid is dropped and replaced by- aldehyde.
• E.g. one carbon carboxylic acid is formic acid, so the name of
the corresponding aldehyde is formaldehyde
CH3 CH2 C
O
H
propionaldehydeH C
O
H
formaldehyde
CH3 C
O
H
acetaldehyde
21Mr. Mote G.D.

22. IUPAC Nomenclature of aldehyde
1. The IUPAC system of naming aldehyde uses the parent
alkane name corresponds to the longest continuous chain
containing the aldehyde group.
2. The final –e of alkane name is dropped and replaced by-al.
3. The numbering of longest continuous chain starts with C-1 as
the carbon bearing the aldehyde group.
4. The substituents are indicated by name and position
number.
C
H
C
H
C
O
H
H2
CH3C
2- pentenal
H C
O
H
Methanal
C
H
C
H
C
O
H
H2
CH3C
2- pentenal
H2
C
H
C C
O
H
H2
CH3C
CH2CH3
2-ethylpentenal
C
H2
C C
O
HH3C
CH3
3-methyl -3-phenyl butenal 22Mr. Mote G.D.

23. Nomenclature of ketone
• Common system:
• ketones are named as dialkyl ketones.
• First member of the series CH3COCH3 is, however, popularly
called acetone.
• The common names of unsymmetrical ketones are obtained
by naming the alkyl groups as separate words in alphabetic
order and adding the third word 'ketone'.
CH3 C
O
CH3
Acetone
CH3 C
O
CH2 CH3
Ethyl methyl ketone
23Mr. Mote G.D.

24. Nomenclature of ketone
IUPAC Nomenclature:
The IUPAC name of ketones is alkanones and the name of an individual member on
the system is derived by dropping the final 'e' of the parent hydrocarbon and
adding the suffix one‘.
While naming higher ketones on IUPAC system, it becomes necessary to assign
positional number to the carbonyl group.
CH3 C
O
CH3
Propanone
CH3 C
O
CH2 CH3
Butanone
CH3 C
O
CH2 CH2 CH3
2-pentanone
24Mr. Mote G.D.

25. Nomenclature of carboxylic acid
• Common system:The longest carbon chain containing the carboxylic group is selected
and the carboxylic acid is named by replacing the 'e' of the corresponding alkane by '-ic
acid'. .
IUPAC Nomenclature:
• The longest carbon chain containing the carboxylic group is selected and the carboxylic
acid is named by replacing the 'e' of the corresponding alkane by '-oic acid'.
• The selected carbon chain is numbered I, 2, 3, 4 etc to indicate the position of the side-
chains attached to it.
C
O
OH
H
CC
H
H2
CH3C
CH2CH3
CH3
2-ethyl-3-methylpentanoic acid
C
O
OHC
H
CH3
H2
CH3C
4 3 2 1
2-methyl butanoic acid
CH3 CH2 CH2
H2
C C
O
OH
Valeric acid
H3C C
H
H2
C C
O
OH
CH3
isovaleric acid
25Mr. Mote G.D.

26. Nomenclature of carboxylic acid
Sr.
No
Common Name structure IUPAC name
1 Formic acid HCOOH Methanoic acid
2 Acetic acid CH3COOH Ethanoic acid
3 Propionic acid CH3CH2COOH Propanoic acid
4 Butyric acid CH3CH2CH2COOH Butanoic acid
5 Valeric acid CH3CH2CH2CH2COOH Pentanoic acid
6 Caproic acid CH3CH2CH2CH2CH2COOH Hexanoic acid
26Mr. Mote G.D.

27. Nomenclature of Acid halides,
anhydrides, Acid amide and ester
Sr.
No
Common Name structure IUPAC name
1 Formyl chloride HCOCl Methanoyl chloride
2 Acetyl chloride CH3COCl Ethanoyl chloride
3 Acetic anhydride CH3CO-O-COCH3 Ethanoic anhydride
4 Propionic anhydride CH3CH2CO-O-COCH2CH3 Propanoic anhydride
5 Formamide HCONH2 Methanamide
6 Acetamide CH3CONH2 ethanamide
7 Ethyl acetate CH3COOCH2CH3 Ethyl ethanoate
8 Ethyl propionate CH3CH2COOCH2CH3 Ethyl propanate
27Mr. Mote G.D.

28. Nomenclature of amine
• Common system:The longest carbon chain containing the amine group is
selected and the amine is named by replacing the 'e' of the corresponding
alkane by '-alkylamine'. .
IUPAC Nomenclature:
• The longest carbon chain containing the amine group is selected and the
amine is named by replacing the 'e' of the corresponding alkane by '-
amine
• The selected carbon chain is numbered I, 2, 3, 4 etc to indicate the
position of the side-chains attached to it.
CH3 CH2 NH2
ethanamine C
H
CH2 NH2H3C
CH3
2-methylpropan-1-amine
C
H
CH2 NH2H3C
CH3
iso butyl amine
CH3 CH2 NH2
ethyl amine
28Mr. Mote G.D.

29. Rules for IUPAC nomenclature for polyfunctional
group
1. In naming molecules containing one or more of the functional groups in Group A, the group of
highest priority is indicated by suffix; the others are indicated by prefix, with priority equivalent
to any other substituents.
2. Priority of function group: Carboxylic acid> ester> acyl halide>amide>aldehyde>ketone>alcohol>
amine> alkene>alkyne>alkane>ether>alkyl halide>nitro alkane
3. Find the highest priority functional group. Determine and name the longest continuous carbon
chain that includes this group.
4. Number the chain so that the highest priority functional group is assigned the parent chain
5. If the carbon chain includes multiple bonds (Group B), replace “ane” with “ene” for an alkene or
“yne” for an alkyne. Designate the position of the multiple bond with the number of the first
carbon of the multiple bond.
6. If the molecule includes Group A functional groups, replace the last “e” with the suffix of the
highest priority functional group, and include its position number.
7. Indicate all Group C substituents, and Group A functional groups of lower priority, with a prefix.
Place the prefixes, with appropriate position numbers, in alphabetical order before the root
name.
C
O
OHC
CH3
C
H
H2
CHO
4-hydroxy-2-methylbut-2-enoic acid
C
H
H
C C
O
H
H
CH3C
CH2CH3
OH
NH2
4-amino-2-ethyl-3-hydroxypentanal 29Mr. Mote G.D.

30. C
O
OH
H2
C
H2
CO
H
C
H2
CCC
H
H3C
NH2
Cl
O
3-(4-amino-1-chloro-3-oxopentyloxy)propanoic acid
C
H
CH2 CH2
ClOH
C
H
NO2
C
H
H2C
1-chloro-4-nitrohex-5-en-3-ol
C
H
CH2 CH2
ClOH
C
H
NO2
C
H
C
H
C
O
H
7-chloro-5-hydroxy-4-nitrohept-2-enal
C
H
CH2 CH2
OHOH
C
H
F
CCC
O
H2CC
O
HO
6-fluoro-7,9-dihydroxy-3-oxonon-4-ynoic acid
HC
CH2
CCH2CC
O
H2CCl
1-chlorohept-6-en-4-yn-2-one
Nomenclature for polyfunctional group
30Mr. Mote G.D.

31. Structural isomerism in organic
compounds
• Structural isomerism : In structural isomerism the isomer
have the same molecular formula but differ in structural
formula in which different atoms are linked in the molecule.
Types of Structural isomerism
1. Chain isomerism- e.g.n-butane and isobutane
2. Position isomerism- e.g. 1-bromobutane and 2-bromobutane
3. Functional isomerism- e.g. ethyl alcohol and dimethyl ether
4. Metamerism-e.g diethyl ether and propyl ether
5. tautomerism – e.g. keto form and enol form
31Mr. Mote G.D.

32. Structural isomerism
1. Chain isomerism: chain isomers have the same molecular formula
but differ in the order in which the carbon atoms are bonded to
each other.
2. Position isomerism: Position isomers have same molecular
formula but differ in the position of a functional group on the
carbon chain.
3. Functional isomerism: Functional isomers have the same
molecular formula but different functional groups.
CH3 CH2 CH2 CH3 CH3 C
H
CH3
CH3
n-butane isobutane
CH3 CH2 CH2
H2
C CH3
H
C CH2 CH3Br
Br
2-bromobutane
1-bromobutane
CH3 CH2 OH CH3 O CH3
dimethyl etherEthyl alcohol
32Mr. Mote G.D.

33. Structural isomerism
4. Metamerism: this type of isomerism is due to the unequal
distribution of carbon atoms on either side of functional
group.
• 5. Tautomerism: It is a special type of functional isomerism in
which the isomers are in dynamic equilibrium
CH3 CH2 O CH2 CH3
diethyl ether
CH3 O CH2
H2
C CH3
methyl propyl ether
CH3 C
O
CH2 COO C2H5 CH3 C
OH
C
H
COO C2H5
Keto form
enol form
Reference: Advanced organic chemistry by Arun Bhal and B.S. Bhal
33Mr. Mote G.D.

34. Thank You
34Mr. Mote G.D.