classification, Nomenclature and Isomerism

1. Classification;
Nomenclature and
Isomerism
For B-Pharm 1st Year
SIX SIGMA INSTITUTE OF TECHNOLOGY AND
SCIENCE, RUDRAPUR
Presented By- Sandhya Punetha
( Assistant Professor)

2. ORGANIC
CHEMISTRY
Organic chemistry is defined as
branch of science which deals with
the study of structure, properties
and reactions of hydrocarbons and
their derivatives.

3. Topic 1- Classification of organic
compounds

4. CLASSIFICATION OFORGANIC COMPOUNDS
Organic Compounds
Open chain/ Aliphatic/Alicyclic Closed chain/ Cyclic
Compounds Compounds
Saturated Unsaturated Homocyclic/Carbocyclic Heterocyclic
Alicyclic Aromatic
Alicyclic Aromatic
Benzenoid Non- Benzenoid

5. ALIPHATIC COMPOUNDS
• These compounds are derived from either
animals or vegetable fats. Therefore, they are
known as aliphatic compounds.
• These compounds contain open chain of carbon
atoms in their molecules and hence are also
known as open chain compounds.
• In these compounds terminal carbon atoms are
free as they are not linked with each other.

6. Types of aliphatic compounds
Saturated Compounds Unsaturated Compounds
These are the compounds
that are saturated or
contain single bond in the
open chain hydrocarbons.
Example- Ethane
H H
H C C H
H H
These are the compounds
which contain single or
double bond in the open
chain hydrocarbons.
Example- Ethene
H H
H C C H

7. CYCLIC COMPOUNDS
• These are the compounds that contain one or
more closed chain or ring of atoms in their
molecules.
• In this case two terminal carbon atoms are linked
with each other.

8. Types of Cyclic Compounds
HH
These compounds are
entirely made up of
hydrogen and carbon
atoms. No other atom is
present in the ring.
Example- Cyclohexane
Homocyclic
Heterocyclic
These compounds contain one or
more heteroatoms like oxygen;
nitrogen; sulphur in their ring.
Example- Furan

9. 1) Homocyclic Compounds-
Types of Homocyclic Compounds
Aliphatic Aromatic
These are the compounds which
resembles with aliphatic compounds
in most of their properties.
Example- Cyclopropane
Cyclobutane
Cyclopentane
These are cyclic unsaturated
compounds. They have derived
their name from Greek word –
Aroma which means fragrant
smell. Since, most of these
compound have sweet smell they
are known as aromatic
compounds.
Example- Benzene.

10. Types of aromatic compounds
Benzenoid Non-Benzenoid
These are the containing more or
more fused benzene rings.
According to the number of
benzene ring they are classified as-
Monocyclic; Bicyclic and Tricyclic.
Example- Benzene
Naphthalene
They are characterized by the
presence of benzene ring to which
other groups are attached.
Example- Toulene C𝐻3
Aniline
N𝐻3

11. 2) Heterocyclic Compounds-
Types of heterocyclic compounds
Alicyclic Aromatic

12. Alicyclic compounds-
• Alicyclic compounds that contain one or more
heteroatoms in their rings are called alicyclic
heterocyclic compounds.
• Example- Tetrahydrofuran O
Tetrahydropyran O

13. Aromatic Compounds-
• These are the compounds that contain one or
more heteroatoms in their ring structure.
• Example- Furan Thiophene
O S

14. HUCKEL’S RULE-
• If the compound is cyclic planar, fully conjugated
and posses (4n+2) pi electrons; then it is an
aromatic compound.
• Conditions- Cyclic
Conjugated bond
Planar
(4n+2) pi electron.

15. Question-
• Which of these is not an aromatic compound?
a) N𝐻2 b) c)