Organic Chemistry
IUPAC
OM PANDEY
IIT DELHI
Catenation in Carbon
Self-linking property of element
Hybridisation of Carbon
O
C CH3 CH CH2
CH2 C CH2
Important Terms
Saturated compounds
Unsaturated compounds
Molecular Formula
Actual number of atoms of each element present in one molecule.
Structural Formula
It indicates the linkage due to covalent bond between different atoms in a molecule.
Expanded structural Formula
Condensed Structural Formula
Bondline Structural Formula
Expanded Condensed Bondline
Structural Formula Structural Formula Structural Formula
H H H
H—C—C—C—H
H H H
CH3 — CH — CH2 — CH3
CH3
Degree of Unsaturation
Hydrogen Deficiency Index
Double Bond Equivalence
Degree of Unsaturation
𝑛𝐻 + 𝑛𝑋 − 𝑛𝑁
DU = (𝑛𝑐 +1) − 2
C6H6O
C6H5Cl
C6Br6
C5H11OCl
Degree of Carbon
Number of carbon atoms attached to a carbon atom.
Primary (1°) carbon Secondary (2°) carbon
Tertiary (3°) carbon Quaternary (4°) carbon
Superprimary
Degree of Carbon
CH3 CH3
CH3 — C — CH — CH2 — CH3
CH3
CH3
Degree of Hydrogen
Is same as the degree of carbon to which it is attached.
CH3
CH3 — C — CH2 — CH — CH3
CH3 CH3
Organic Compounds
Acyclic Compounds or Organic Compounds
open chain Closed Chain Compounds
(Aliphatic compounds)
Alicyclic Aromatic
Saturated Unsaturated
hydrocarbon hydrocarbon
Alkane Alkene , Alkyne Homocyclic Heterocyclic
Homocyclic Heterocyclic
O NH N
H
IUPAC Nomenclature
Word Root : Number of carbon atoms present in the main chain
Number of Carbon Word Root
Primary Suffix : It indicate the saturation or unsaturation existing in the main
chain.
Primary Suffix Word Root
ane
ene
diene
yne
diyne
enyne
Secondary suffix : It is used for the principal functional group.
Functional Group :
Primary Prefix : ‘Cyclo’ word is used for alicyclic compounds.
Secondary Prefix : Normal substitutents and junior functional groups are treated as a
substituent, then their name is treated groups are always cited in
the prefix.
–R
– OR
–X
– NO2
–N = O
Naming of Saturated Hydrocarbons
Rules for selection of main chain and numbering :
Maximum number of Carbon
Number of sub.
Lowest set of locants
Alphabetical Order.
Naming of Saturated Hydrocarbons
C
C—C—C—C—C
C—C—C—C—C—C—C
C
Naming of Saturated Hydrocarbons
C C C C
C—C—C—C—C—C—C—C C—C—C—C—C—C—C—C
C—C—C C—C—C
Cl Cl
C—C—C—C—C—C C—C—C—C—C—C
Cl Cl Cl Cl
Naming of Saturated Hydrocarbons
C—C—C—C—C—C—C—C
C C—C
Practice Time
3 – Ethyl – 2 – methylpentane
2, 4 – Dimethylhexane
2, 2, 5 – Trimethylheptane
3 – Ethyl – 4 – methylhexane
C—C—C—C—C
Cl Br
C—C—C—C—C
Cl Br
Cl
C—C—C—C—C
Cl Br
Naming of Unsaturated Compounds
Maximum number of > Number of sub. > Lowest set of locants > Alphabetical Order.
carbon with M. B.
CH3 — CH = CH2
CH3 — CH2 — CH = CH2
CH3 — CH = CH — CH — CH3
|
CH3
Naming of Unsaturated Compounds
Maximum number of > Number of sub. > Lowest set of locants > Alphabetical Order.
Carbon with M. B.
Cl
|
CH3 — C — CH2 — CH = CH2
|
Cl
C CH C CH
HC C — C CH
Rules for writing Radicals
Alkane
Alkene
Alkyne
Benzene
Benzene Radical
CH2 —
CH
C
CH2
CH — R
Normal (n) : Radical or hydrocarbon which has straight chain
n – butane
n – pentane
n – hexane
Iso : Two methyl group at the end of linear chain
Isobutane
Isopentane
Isohexane
Neo :
Neopentane
Neohexane
Iso-octane
Secondary :
Secondary butyl
Tertiary :
Tert. butyl Tert. pentyl
Complex Radical
C—C—C—C—C—C—C—C—C
C—C
C—C
C
Naming of Cyclic Hydrocarbon
Maximum number of > Number of sub. > Lowest set of locants > Alphabetical Order.
Carbon with M. B.
All the factors are similar in cyclic and acyclic part then Cyclic > Acyclic
Naming of Cyclic Hydrocarbon
C — C — Cl C—C—C
C—C—C
Cl
Cl
Cl
Br Br
I
Cl
Naming of Functional Groups
12 Functional Groups
Class Suffix Prefix
R — COOH Oic acid (carboxylic acid) Carboxy
R — SO3H Sulphonic acid Sulpho
O O
|| || Anhydride (carboxylic anhydride)
—C—O — C —
O
|| -oate (Carboxylate) Alkoxy Carbonyl
— C — OR
O
|| Oyl halide (Carbonyl halide) Halo Carbonyl
—C— X
Class Suffix Prefix
O
|| amide (carboxamide) Carbamoyl
— C — NH2
R—C N nitrile (carbonitrile) cyano
O
|| al (carbaldehyde) formyl / Oxo
—C—H
O
|| one Oxo / Keto
—C—
Class Suffix Prefix
— OH ol hydroxy
— SH thiol mercapto
— NH2 amine amino
Functional Groups
7 Functional group 5 Functional group
O O
|| ||
– SO3H – OH
—C — NH2 —C — H
O O
|| || – NH2 – SH
—C — OR —C — OH
O O O O
|| || || ||
—C — O — C — R —C — Cl —C —
—CN
7 Functional group 5 Functional group
Rule : If above 7 functional groups Rule : Numbering is done from the
are present in carbon chain, it side of the chain which gives
is always given the position 1. the lowest number to functional
group
O
CH3 — C — OH CH3 — CH2 — CH — CH3
OH
O
CH3 — CH2 — CH2 — CH2 — C — H
Selection of main chain / numbering
Functional group > Multiple Bonds > No. of carbon atoms > No. of substituents
> lowest locant > alphabetical order
Note : If first alphabet of the secondary suffix is a / e / i / o / u then e of primary
suffix will be dropped.
Lowest locant Functional group > Multiple Bond > Substituents
The senior functional group makes the suffix while other junior functional
group are written as prefix in alphabetical order.
O
CH3 — C — CH2 — CH2 — OH
Alcohols
Functional Suffix Prefix
group
CH3 — OH
CH3 — CH — CH3
OH
Alcohols
OH OH
CH3
CH3 — C — CH3
OH
CH3 — CH — CH — CH3
OH CH3
Alcohols
OH OH
CH3
OH
OH
OH
OH
Amines
Functional Suffix Prefix
group
NH3
CH3 — CH2 — NH2
CH3
CH3 — CH2 — NH
N
Amines
CH3 — CH2 — NH2
CH3 — CH — CH3
NH2
CH3 — CH2 — NH — CH3
CH2 = CH — CH2 — NH2
Amines
NH2
NH2
OH
NH2
Ketones
Functional Suffix Prefix
CH3 — C — CH3 group
CH3
O
Carboxylic Acid
O Functional Suffix Prefix
|| group
H — C — OH
O
||
C — OH
C — OH
||
O
Carboxylic Acid
C — OH
||
O
C — OH
||
O
Aldehydes & Ketones
Functional Suffix Prefix
group
CH3 — CH = O
CH3 O
CH3 — CH2 — CH2 — CH — CH2 — C — H
Br
Aldehydes & Ketones
Functional Suffix Prefix
O group
CH3 — CH2 — CH CH — C — H
CH3 — CH2 — C — CH2 — C — H
O
Aldehydes & Ketones
O
C—H
C—H
CH2 — CH3
Acid Anhydride
C — OH HO — C
O
+ O
O O
CH3 — C — OH + HO — C — CH3
Acid Anhydride
C — OH O
O + HO — C — CH3
O
||
C
O
C
||
O
O
C C
|| ||
O O
O
||
Note 1. —C — OH
O O
C — OH C — OH
C — OH
O
O
C — OH
O
||
Note 2. —C — H
O
C—H
O
C—H
Ester
O
||
R' — C — O — R
O
||
1. H — C — O — CH3
O
||
2. CH3 — C — O — CH2 — CH3
O
||
3. CH3 — CH2 — C — O — CH2 — CH3
Amides
O Functional
|| Suffix Prefix
group
1. H — C — NH2
O
||
C — NH2
2.
O
||
3. CH3 — C — NH2
Nitrile
Functional Suffix Prefix
group
CN
CH3 — C N
Acid Halide
Functional
O Suffix Prefix
|| group
C — Cl
O
||
CH3 — C — Cl
Ether
R` — O — R
CH3 — O — CH3
CH3 — O — CH2 — CH3
O — CH2 — CH3
