CHEM CH EMIS ISTR TRY Y
A-10, "GAURAV "GAURAV TOWER", TOWER", Road No.-1, I.P.I.A., I.P.I.A., Kota-324005 (Raj.) INDIA IND IA Tel.: 0744-2423738, 2423739, 2421097, 2424097 Fax: 0744-2436779 E-mail:
[email protected] [email protected] n Website : www.bansal.ac. www.bansal.ac.in in
NOMENCLATURE OF ORGANIC COMPOUNDS Mainly three systems are adopted for naming an organic compound : (i)
Common Names or Trivial System
(ii)
Derived System
(iii)
IUPAC system or Geneva System
–
COMMON OR TRIVIAL SYSTEM On the basis of
Source
Property
Discovery
Structure
(i) On the basis of source from which they were obtained. S. No . Organic Compound
Trivial Name
1.
Wood spirit or Methyl
Obtained by destructive distillation
spirit
of wood.
CH3OH
S o u r ce
2.
NH2CONH2
Urea
Obtained from urine
3.
CH4
Mars Marsh h ga gas (fi (fire re damp damp))
It was was prod produc uced ed in mars marsh h pla place ces. s.
4.
CH3COOH
Vinegar
Obtained from Acetum - i.e. Vinegar
Oxalic acid
Obtained from oxalis plant.
5.
COOH | COOH
6.
HCOOH
Formic acid
Obtained from formicus [Red ant]
7.
CH 3 – CH – COOH
Lactic acid
Obtained from lactous (milk)
| OH
8.
CH 2 – COOH | CH(OH)COOH
Malic acid
Obtain from Apple
9
CH3CH2CH2COOH
Butyric acid
Obtained from butter.
10.
CH3(CH2)4COOH
Caproic acid
Obtained from goats.
11.
C2H5OH
Grain alcohol
Obtained from barley.
Nomenclature of Organic Compound
[2]
NOMENCLATURE OF ORGANIC COMPOUNDS Mainly three systems are adopted for naming an organic compound : (i)
Common Names or Trivial System
(ii)
Derived System
(iii)
IUPAC system or Geneva System
–
COMMON OR TRIVIAL SYSTEM On the basis of
Source
Property
Discovery
Structure
(i) On the basis of source from which they were obtained. S. No . Organic Compound
Trivial Name
1.
Wood spirit or Methyl
Obtained by destructive distillation
spirit
of wood.
CH3OH
S o u r ce
2.
NH2CONH2
Urea
Obtained from urine
3.
CH4
Mars Marsh h ga gas (fi (fire re damp damp))
It was was prod produc uced ed in mars marsh h pla place ces. s.
4.
CH3COOH
Vinegar
Obtained from Acetum - i.e. Vinegar
Oxalic acid
Obtained from oxalis plant.
5.
COOH | COOH
6.
HCOOH
Formic acid
Obtained from formicus [Red ant]
7.
CH 3 – CH – COOH
Lactic acid
Obtained from lactous (milk)
| OH
8.
CH 2 – COOH | CH(OH)COOH
Malic acid
Obtain from Apple
9
CH3CH2CH2COOH
Butyric acid
Obtained from butter.
10.
CH3(CH2)4COOH
Caproic acid
Obtained from goats.
11.
C2H5OH
Grain alcohol
Obtained from barley.
Nomenclature of Organic Compound
[2]
(ii) On the basis of property
1. Glucose - Sweet in test
2. Gl G lycol - Sweet poisnous
3. Glycerol - Sweet (Glycus - Sweet) (iii) On the basis of discovery
1. RMgx (Grigard Reagent)
2. R 2Zn (Frankland reagent)
(iv) (iv) On the basis of structure structure S .No . (i) (ii) (iii) (iv) (v) (vi) (vii) (viii) (ix) (x)
No. of Carbon atom 1C 2C 3C 4C 5C 6C 7C 8C 9C 10C
Word Root Meth Eth Prop But Pent Hex Hept Oct Non Dec
Common Names for Hydrocarbon Derivetives
S S..No.
Compound
Name
1. 2. 3. 4. 5.
R – X R – OH R – SH R – NH2 R – O – R R
Alkyl halide Alkyl alcohol Alkyl thio alcohol Alkyl amine Dialkyl ether
6. 7.
Dialkyl ketone R R – NH – R
Dialkyl amine
8. 9.
Trialkyl amine R’ R – O – R
Alkyl alkyl’ ether Alkyl alkyl’ ketone
10. 11.
R’ R – NH – R
Alkyl alkyl’ amine Alkyl alkyl’ alkyl” amine
12.
R is termed as alkyl - -)
Nomenclature of Organic Compound
[3]
GROUPS
Atom or a group of atoms which possess any ‘free valency’ are called as Groups. If their are two structure of same molecular formula then some prefix (n, iso, neo) are used two differenciate them. Normal group : –
(a) It is represented by ‘n’. (b) Groups having no branch (Straight chain). (c) Free bond will come either on Ist carbon atom or on last carbon atom. n – butyl CH3 – CH2 – CH2 – CH2 – n – propyl CH3 – CH2 – CH2 – Iso group : –
When one methyl group is attached to the second last carbon of the straight carbon chain is named as iso group. CH 3 ! C H ! CH 2 !
H3 C ! CH ! | CH3
e.g.
CH 3 ! C H ! CH 2 ! CH 2 !
|
|
CH 3
Isopropyl
CH 3
Isobutyl
Isopentyl
Exception :
CH 3
CH 3
|
|
CH 3 ! C
CH 3 ! C! CH 2 ! C H ! CH 2 ! |
CH 3
!
|
|
CH 3
C H ! CH 2
!
|
CH 3 CH 3
(i) Iso octyl
(ii) Iso heptyl
Neo group : – (a) When two methyl groups on second last carbon of a straight carbon chain is attached to other four carbon atom group is named as neo group. (b) It is represeted by following structure C | C!C!C | C
(c)
C | for eg. C ! C ! C – Neo pentyl | C
There should be one 4° carbon and atleast three methyl group on 4° carbon.
NOTE : (Optically Active) = If all valency are attached to different atoms. Amyl group : – H | CH3 ! CH2 ! C ! CH 2 | CH3
Active amyl
!
CH3 ! CH2 ! CH – | CH2 | CH3
Secondary amyl
CH3
!
CH2
!
CH2
CH ! | CH3
!
Active secondary amyl
Nomenclature of Organic Compound
CH3
! CH !
CH ! | | CH3 CH3
Active iso secondary amyl
[4]
Secondary group : –
(a) The carbon having free valency attached to two carbon is called secondary carbon. (b) It is represented by following structure. C ! C ! C ! C |
eg. (i)
CH 3 ! CH ! CH 2 ! CH 3
(ii)
CH 3 ! CH ! CH 2 ! CH 2
|
|
(secondary butyl)
– CH 3
(secondary pentyl)
Tertiary group : –
(a) The carbon having free valency attached to three other carbon . C |
(b) It is represented by following structure -
C ! C! C |
CH3
CH3
|
e.g.
|
(i) CH3 ! C! CH3
CH3 ! C! CH2 ! CH3
|
|
(Tertiary butyl)
(Tertiary pentyl)
Alkyl group : –
When a hydrogen is removed from Alkane (saturated hydrocarbon) then alkyl group is formed. A bond is vacant on alkyl group on which any functional group may come. # Alkyl alkane " " !H (CnH2n+2)
(CnH2n+1)
e.g.
# CH3 – (i) CH4 " " !H Methane
Methyl
# CH3 – CH2 – (ii) CH3 – CH3 " " !H Ethane (iii) CH3 – CH2 – CH3 Propane
ethyl CH3 – CH2 – CH2 – n-Propyl
– H
CH – 3 CH – CH 3 iso-Propyl
(iv) CH3 – CH2 – CH 2 – CH 3 n-Butane
– H
CH – – CH – 3 CH 2 2 CH 2– n-Butyl CH – 3 CH – CH2 – CH 3 Sec. Butyl
(v) CH3 – CH– CH3
– H
CH3 – CH – CH2 – iso-butyl
iso-butane CH3 – C – CH3 tertiary-butyl
Nomenclature of Organic Compound
[5]
CH3 – CH2 – CH2 – CH – – 2 CH 2 n-pentyl (vi) CH3 – CH– CH2 – CH2 – CH3 n-pentane
– H
CH3 – CH – CH2 – CH2 – CH3 active secondary amyl C2H5 – CH – C2H5 secondary amyl
CH3 – CH – CH2 – CH – 2 iso-pentyl CH3 – C – CH2 – CH3 – H
(vii)
tertiary-pentyl C2H5 – CH – CH2 –
iso-pentane
active amyl CH3 – CH – CH– Active isosecondary amyl
CH3
CH3 – H
(viii) CH3 neo-pentane
CH3 neo-pentyl
Alkenyl group : – alkene (CnH2n)
CH2 = CH Vinyl
–
CH2= CH – CH2 – Allyl
!H
# Alkenyl (CnH2n – 1)
CH3 – CH = CH – Propenyl(1-propenyl)
CH3 ! C $ CH2 |
Isopropenyl (1-methyl-1-ethenyl)
Nomenclature of Organic Compound
[6]
Alkynyl group –
# Alkynyl alkyne " " !H
(CnH2n – 2)
CH % C Ethynyl
(CnH2n – 3)
CH % C – CH2 – Propargyl (2-propynyl)
–
CH3 – C % C – Propynyl (1-propynyl)
Alkylidene group – – 2 H
" " " " " # Alkylidene alkane " from same carbon
Alkylene group alkane
– 2 H " " " " " " " # Alkylene from different carbon
-
Position of double bond : –
In an unsaturated hydrocarbon if the position of double bond is on I st or last carbon then it ’s prefix will be & (alpha) if it is on 2 nd carbon it is termed as ' (Beta) & the ( (gamma) & ) (delta) and so on. eg.
H2C = CH
–
CH2
H3C – CH = CH
–
–
CH3
CH3
H3C – CH2 – CH = CH2 H2C = CH
–
& - butylene ' - butylene & - butylene
CH3 or H3C – CH = CH2
H3 C ! C $ CH2 | CH3
(Both are same positions, propylene)
Isobutylene
CH3 – CH2 – CH=CH – CH2 – CH3
( - hexylene
CH3 – CH2 – CH2 – CH=CH – CH2 – CH2 – CH3 ) - octylene COMMON
– NAMING OF DIHALIDES
(a)
When two same halogen atoms are attached to the same carbon such compounds are called Gemdihalides.
(b)
Common names of such compounds are alkylidene halides I
Cl
eg. :
Cl Ethylidene chloride
Exception : Methylidene halide (wrong)
I H3 Isobutylidene Iodide X X
Methylene halide (right)
Nomenclature of Organic Compound
[7]
(c) When two same halogen atoms are attached to adjacent carbon, these are called as vicinal dihalides. Common names of such compounds are alkylene halide.
CH3
eg
! CH !
|
CH2 |
+
+
Cl | H3 C ! C ! CH2 | CH3
Propylene Iodide
!
Cl
Isobutylene chloride
(d) When two same halogen atoms are attached at the two ends of a carbon chain its common naming will be polymethylene halide. poly’ word indicates the number of – CH2 – groups.
‘
CH2 –
–
2
3
4
Poly
di
tri
tetra penta Hexa
CH2 |
eg.
!
CH2
!
+
5
6
CH2 | Br
CH2 | +
Trimethylene Iodide
!
CH2 ! CH2 ! CH2 ! CH2 | Br
Pentamethylene Bromide
Exception : –
CH2 – X dimethylene halide
(wrong)
| CH2 – X ethylene halide
(right)
COMMON - NAMING OF DI-HYDROXY COMPOUNDS
(a) When two – OH groups are attached to adjacent carbon atoms they are termed as alkylene glycol. CH3
!
CH2
CH ! CH2 | | OH OH
!
OH | CH3 ! CH 2 ! C ! CH 2 ! OH | CH3
Butylene glycol
Active amylene glycol
(b) When two – OH group are attached at the two ends of a carbon chain, these compounds are named as polymethylene glycol. Poly
# Number of CH 2 groups.
CH eg. : | 2 OH
!
CH2
CH2 | OH
! CH2 !
CH2 | OH
Tetra methylene glycol
!
CH2 ! CH2 ! CH2 ! CH2 ! CH2 | OH
Hexamethylene glycol
Exception :
CH2
–
OH
Dimethylene glycol (wrong)
| CH2 – OH
Ethylene glycol
(right)
Nomenclature of Organic Compound
[8]
COMMON-NAMING OF THE FUNCTIONAL GROUP HAVING CARBON
(Common naming for Hydrocarbon derivatives) S.No.
Functional group
Suffix
(i)
O || ! C ! OH
-ic Acid
O
O
||
(ii)
||
-ic anhydride
O || !C ! O ! R
(iii)
-ate
(iv)
O || !C ! NH2
-amide
(v)
O || !C ! X
-yl halide
(vi)
O || !C ! H
-aldehyde
(vii)
–
(viii)
C % N
!N $
-o-nitrile -o-isonitrile
C
Prefix : –
1 Carbon
# Form-
2 Carbon # Acet-
3 Carbon # Propion-
4 Carbon #
#
Butyr |
#
Normal Iso
5 Carbon # Valer
3 C + (=) double bond = Acryl -
O || eg. H! C !H
Formaldehyde O || CH3 ! CH2 ! C ! Cl
Propionyl chloride
4 C + double bond = Croton-
O || CH3 ! C ! O ! H
Acetic Acid O || CH3 ! CH ! C ! NH 2 | CH3
Isobutyramide
O || CH3 ! C ! H
Acetaldehyde
Nomenclature of Organic Compound
[9]
NOMENCLATURE OF ESTER O || !C ! O ! R
The group which is attached to the oxygen is written as alkyl & the remaining structure is named on the basis of Functional Group suffix.
eg. (i)
O || H ! C ! O ! CH3 (ii)
O || CH3 ! O ! C ! H
Methyl formate O || (iv) CH3 ! C ! O ! CH3
Methyl formate
(v)
Acetic acid
O O || || (vi) ! ! ! O ! CH2 ! CH 3 CH CH C CH3 ! C ! O ! CH2 ! CH3 3 2
Methyl acetate
(vii)
O || (iii) CH3 ! C ! O ! H
Ethyl acetate
O || CH2 $ CH ! C ! O ! CH 2 ! CH3
Ethyl propionate
O || (viii) CH 3 ! CH $ CH ! C ! O ! CH 3
Ethyl acrylate
Methyl crotonate
NOMENCLATURE OF ANHYDRIDE
Rule : – Add the total number of carbon atoms & divide it by 2, the substract will give you the number of C - atom. Now name it according to suffix use for anhydride. Total = Substract 2
= Number of C atom O
4 = 2 2
||
O ||
O
6 = 3 2
||
Acetic anhydride
O ||
Propionic anhydride
If R , R ’, You need not to find out substract. O eg.
||
O ||
Acetic propionic anhydride (right) Propionic Acetic anhydride (wrong) Divide it in two parts as above & name it by suffixing ic anhydride (alphabatically) CH3 O O
eg.
||
O
|
||
||
O |
||
CH3 O
Nomenclature of Organic Compound
[10]
Butyric propionic anhydride
Isobutyric Secondary valeric anhydride
O ||
O
Acrylic anhydride
||
O DERIVED
SYSTEM
According to this system name to any compound is given according to the parent name of the homologous series. This system is reserved for the following nine homologous series. S.No.
Name of Homologous series
Derived Name
Structure of group |
1.
Alkane
Methane
2.
Alkene
Ethylene
3.
Alkyne
Acetylene
!C!
|
>C=C< !C %
C!
|
4.
Alkanol
Carbinol
!C!
|
OH
|
Alkanal
Acetaldehyde
!C!
6.
Alkanoic acid
Acetic acid
!
7.
Alkanoyl halide
Acetyl halide
!C!
8.
Alkanamide
Acetamide
–C – CONH 2
5.
|
CHO
|
C
COOH
!
|
| |
COX
|
9.
Alkanone
Acetone
! C!
|
|
C! C! ||
|
O
Types of Ethylene: – (Symmetrical & Unsymmetrical) (a) Symmetrical : – In the given two alkyl groups one group is attached to the one carbon of ethylene & next on the next carbon. (b) Unsymmetrical : – When both the given groups are attached on the same carbon. Note : Symmetrical & Unsymmetrical : – Terms are used only when two alkyl groups are given.
eg. Symmetrical dimethyl ethylene
Unsymmetrical dimethyl ethylene
Symmetrical ethyl methyl ethylene
Nomenclature of Organic Compound
[11]
Tri methyl ethylene
Tetra methyl ethylene CH3 – C % C – CH3
Dimethyl acetylene
IUPAC NOMENCLATUR
The name consists of three parts: Prefix Secondary [Details of substitutents]
+ Primary [Nature of Carbon chain cyclic/acylic]
Word root
Suffix
+
[No. of carbon atoms in the principal chain]
Primary [Nature of carbon carbon bond]
Secondary [Details of functional group]
Primary Prefix : It represents the nature of the principal / parent chain. Nature of chain
Primary Prefix
Acyclic / Non-cyclic Cyclic Bicyclic Tricyclic Spiro
–
Cyclo Bicyclo Tricyclo Spiro
Secondary prefix : It represent substituents. Word root : It represents the number of carbon atoms in the principal / parent chain. No. of carbon atoms
1 2 3 4 5 6 7 8 9 10 11 12 13 20 30 40
Word root
Meth Eth Prop But Pent Hex Hept Oct Non Dec Undec Dodec Tridec Eicos Triacont Tetracont
Nomenclature of Organic Compound
[12]
Primary Suffix :
It represents the nature of C – C bonds in the principal/ parent chain (whether single bond, double bond or triple bond).
Nature of bond
Primary suffix
Saturated C – C single bond
ane
Nature of bond
Primary suffix
Unsaturated C = C bond C % C bond 2C = C bonds 2C % C bonds
ene yne diene diyne
C = C + C % C
* ene + yne = enyne
* If secondary suffix starts from a vowel or y then the last ‘e’ of first suffix is omitted. Secondary suffix : is used for functional groups. SATURATED UNBRANCHED HYDROCARBONS
IUPAC name = Word Root + Primary Suffix e.g.
CH4
Meth + ane
=
Methane
CH3 – CH3
Eth + ane
=
Ethane
CH3 – CH2 – CH3
Prop + ane
=
Propane
But + ane
=
Butane
Pent + ane
=
Pentane
Hex + ane
=
Hexane
CH3(CH2)9CH3
Undec + ane
=
Undecane
CH3(CH2)28CH3
Triacont + ane
=
Triacontane
SATURATED BRANCHED CHAIN HYDROCARBONS
Principal / parent chain Branch / Substitutent
Nomenclature of Organic Compound
[13]
Rules for naming Branches R – H " # R – !H
Alkane (CnH2n+2)
Alkyl substituent (CnH2n+1)
e.g. Alkane
Alkyl
(1)
CH4
–
(2)
C 2H6
–
IUPAC names
CH3
Methyl
C2H5
Ethyl
Naming of complex alkyl groups (i) Longest chain in a branch is selected starting from the same and where it originates from. (ii) Numbering is started from the originating end of a branch.
(3)
CH2CH2CH3
C 3H8
Propyl
–
CH3
1
– CH
1 – Methyl ethyl
CH3 2
(4)
C4H10
C4H9
–
4
3
2
1
CH3CH2CH2 CH2 – 1
2
Butyl
3
CH3 –CH–CH2– CH3
1-methyl propyl
CH3 3
2
2-methyl propyl
1
H3C –CH–CH2– 2
CH3
1
1,1-dimethylpropyl
H3C – C– CH3
CH3 5
(5)
4
3
2
1
CH3 –CH– C – CH2 –CH2–
3,3,4-trimethyl-pentyl
CH3 CH3
Nomenclature of Organic Compound
[14]
SATURATED BRANCHED CHAIN HYDROCARBONS
Rules
(1)
Longest chain rule : Select the longest possible carbon chain as the parent chain or principal carbon chain. All other carbon chains will be considered as side chain or substituents. C – C – C – C – C C – C
Longest chain containing 6 carbon atoms
C
(2)
If there is more than one longest chain possible then select the chain which contains maximum number of side chains C
C
C – C – C – C – C
C – C – C – C – C
C – C
C – C
Correct
(3)
Incorrect
Lowest set of locant rule : The number given to the side chain is locant. While numbering the parent chain, lowest set of locants rule needs to be followed. According to this rule, that set of locants will be considered which has got a lower number at the first point of difference.
I = ( 2, 2, 3, 6, 8)
Correct
II = ( 2, 2, 4, 4, 5)
Incorrect
First point of difference *
First set will be considered in this case. 4
2 1
3
6
8
1
(a)
11
6
2 3
4
8 7
5
2,4,6-Trimethyldecane (Correct)
12
10 9
7
5
9
10
3,4,5-Trimethyldecane (correct)
Side chains are always written in alphabetical order. 4 2
5 3
1
3-Ethyl-2-methylpentane
Nomenclature of Organic Compound
[15]
(b)
Di, tri, tetra etc. are not considered in comparing alphebetical order.
5
1
3
4
(c)
3 – Ethyl – 2, 4 – dimethyl hexane
6
2
If lowest set of locants rule is not applicable then numbering is done according to alphabetical order. 2
4
3
1
6
5
6 7
7
4
3
2 1
Locant – 3, 5 (incorrect)
Locant – 3, 5 (correct)
(d)
5
If Di, tri, tetra etc. are part of name of complex name then they considered in alphabetical order. 6
2 3
1
7
5
5
(e)
7
4-(1,1-Dimethyl)-3, 5-diethylheptane
1
3
5-Ethyl-3,4-bis(1-methylethyl)-2-methylheptane
2
4
6
4
bis , tris, tetrakis are used for complex alkyl substituents
e.g.
(1)
1
2
3
4
5
CH3 –CH 2–CH– CH 2 – CH3
3-methylpentane
CH3
(2)
1
2
3
CH3 –CH 2–CH – CH 2 – CH3
3-ethylhexane
4 CH 2 5 CH 2 3
(3)
— CH3 6
4
5
CH3 –CH 2–CH– CH 2 – CH3
3-ethyl-2-methylpentane
H3C – CH – CH3 2
1
Nomenclature of Organic Compound
[16]
1 CH 3 2 CH
— CH3
CH3 –CH 2–CH – CH 2 – CH3
(4)
3,3-diethyl-2,4-dimethyl-pentane
3
4 CH
— CH3
5 CH 3
CH3 1
(5)
2 3
5
4
6
2,2,5-trimethylhexane
CH3 –C–CH2– CH2 – CH – CH3 CH3 5
6
(6)
CH3 2
3
4
1
3-Ethyl-4-methylhexane
CH3 –CH2– CH — CH – CH2 – CH3 CH3 CH2 CH3 H3C
CH3
CH 1
(7)
2
3
4
5
6
7
CH3 –CH– CH2— C — CH2 – CH2– CH3 CH3
CH
H3C
CH3 CH2 – CH3
6
7
5
4
3
2
1
CH3 –CH2– CH2 — CH – CH – CH2 – CH3
(8)
2-methyl-4-bis(1-methylethyl)heptane
4-(1,1-dimethylethyl)-3-ethylheptane
H3C – C – CH3 CH3 UNBRANCHED UNSATURATED HYDROCARBON
Numbering of carbon chain Rule-1 : If unsaturated bond is present in the molecule at the terminal carbon, then numbering done from the side of unsaturated carbon. 1
2
1
2
3
4
eg. CH2 = CH – CH 2 – CH 3 3
4
eg. CH % C – CH2 – CH3
But – 1 – ene
But – 1 – yne
Rule-2 : If unsaturated bonds like double bond and triple bond is present at terminal carbon, then numbering always done from double bonded terminal carbon. (Double bond preferred over triple bond when both bonds are at same position) 1
2
3
4
eg. CH2 = CH – C % CH
But – 1 – en – 3 – yne
Nomenclature of Organic Compound
[17]
Rule-3 : If unsaturated bonds like double bond or triple bond is present at terminal carbon, then numbering is done from either way.
eg.
1 2 3 4 CH2 = CH – CH = CH2
But – 1, 3 – diene
1 2 3 4 eg. CH 2 % C – C % CH
But – 1, 3 – diyne
Rule-4 : If triple bond is present at terminal carbon and double bond is located at any carbon except other terminal carbon. Then numbering is done from triple bond. 1 2 3 4 5 CH % C – CH $ CH – CH3
Pent – 3 – en – 1 – yne
Rule-5 : If double bond is present at terminal carbon and triple bond is present at any other position except other terminal carbon, then numbering is done from double bonded terminal carbon. 1
2
3
4
5
eg. CH2 = CH – C % C – CH3
Pent – 1 – en – 3 – yne
BRANCHED UNSATURATED HYDROCARBON
Longest chain : Rule-1 : If unsaturated bonds like double bond or triple bond is present in the molecule, then that parent chain is considered which is containing unsaturated bonds like double bond or triple bond. 7
6
5
4
3
2
1
eg. CH3 – CH2 – CH2 – CH2 – CH – CH = CH2
| CH2 – CH2 – CH3
eg.
Parent chain
5 6 4 3 2 1 CH3 – CH = CH – CH – CH = CH2 | CH2 – CH2 – CH3
Rule-2 : A primary suffix is added to the word root to indicate presence at double or triple bond in the parent chain. For one double bond = Word root + locant + ene For one triple bond = Word root + locant + yne
In case the parent chain contains two or more double bonds, the prefixes di, tri, tet ra, etc. are used before primary suffix. For two double bonds = Word root + locant + diene For two triple bonds = Word root + locant + diyne Numbering of carbon chain : Rule-1 : In branched alkene, select that parent chain which is containing maximum unsaturated double bond or triple bond and follow properly of lowest locant rule. 2 1 CH = CH2
eg.
eg. Cyclohexyl eth -1-ene
CH3 CH3 |5 1 2 4 7 6 3 CH3 – CH = C – CH – CH – CH2 – CH3 4, 6-dimethyl hept-2-ene
Nomenclature of Organic Compound
[18]
3 1 2 CH2 – CH = CH2 6 4 5 eg. CH3 – CH2 – CH2 – CH2 – C = CH – CH3
1 2 C % CH
eg. Cyclohexyl eth -1-yne
4 – Butylhexa-1-4-diene
Rule-2 : In branched alkene, if unsaturated double bond or triple bond is present in the cyclic ring, then numbering is done from double bonded carbon of the cyclic ring and follow lowest locant rule properly. 6
eg.
5 4
1 CH2 – CH3
2 3 1-ethyl cyclohex-1-ene
IUPAC NAMING OF ORGANIC COMPOUND CONTAINING FUNCTIONAL GROUPS
In IUPAC nomenclature functional groups are catagorized into two type. TypeI : Groups of this type are not considered as functional groups in IUPAC nomenclature. They are considered as substituents & therefore represented by prefix. type I functional group & their prefix are shown below: Groups – F – Cl – Br – I – NO 2 – NO – OR
Prefix fluoro chloro bromo iodo nitro nitroso alkoxy
– C – C –
epoxy
O
Rules for their nomenclature : Rule I : If two substituents are present on same position from different ends, then priority is decided on the basis of alphabetical order. 5
4
3
2
1
CH2 – CH2 – CH2 – CH2 – CH2 | | Cl Br Rule II : If multiple bond and type I functional group both are present, the priority is given to multiple bond. 1
2
3
4
5
H3C – CH = CH – CH – CH2 – Cl Rule III : These groups are written is alphabatical order in IUPAC name.
eg.
(i)
5
4
3
2
1
CH3 – CH2 – CH2 – CH – CH3 | F
2-fluoropentane
Nomenclature of Organic Compound
[19]
(ii)
(iii)
F | H3C – CH – CH2 – CH2 – CH – Cl | CH2 | CH3 F | H3C – CH 2 – CH – CH2 – CH – Cl | CH2 | CH3
5-chloro-2-fluoroheptane
3-chloro-5-fluoroheptane
(iv)
H3C – CH – CH – CH – CH3 | | | CH2 NO2 CH2 | | CH3 CH3
3, 5-dimethyl-4-nitro heptane
(v)
CH2 – CH2 – CH – CH2 – C – CH2 – CH3 | | || NO I CH2
2-ethyl-4-iodo-6-nitroso hex-1-ene
(vi)
HC = CH – C – CH2 – CH2 – Cl || | Cl CH2
1-chloro-3-chloroethylbuta-1, 3-diene
(vii)
H 3C – CH2 – O – CH2 – CH3
ethoxy ethane
(viii)
H3C – CH2 – O – CH2 – CH2 – CH3
1-ethoxy propane
(ix)
H3C – CH2 – CH – O – CH2 – CH2 – CH3 | CH3
2-propoxy butane
(x)
H3C – CH2 – CH – O – CH – CH3 | | CH3 CH3
2-(methyl ethoxy) butane or 2-isopropoxy butane
Epoxides :
(1)
CH3 – CH – CH2
1, 2-epoxy propane
O
(2)
3, 4-epoxy heptane O
Nomenclature of Organic Compound
[20]
Cl (3)
2-chloro-5, 6-epoxy octane O O
(4)
1, 3-epoxy propane
O
(5)
2, 4-epoxy-3-methyl pentane
Type-II : Groups of this type are treated as functional groups and represented by suffix in IUPAC nomenclature. Priority table for functional group.
S.No.
Functional group
Name
Suffix
Prefix
(1)
O || ! C ! OH
Carboxylic acid
oic acid
Carboxy
SO3H
Sulphonic acid
sulphonic acid
Sulpho
Acid anhydride
oic anhydride
–
(2)
–
!C!O!C!
|| O
(3)
|| O
(4)
! C ! OR || O
Ester
(5)
! C ! Cl || O
Acid chloride
oyl chloride
Chlorocarbonyl
(6)
! C ! NH 2
Amide
amide
Carbamoyl
C % N
Cyanide
nitrile
Cyano
N % C
Isocyanide
isonitrile
Isocyano
CHO
Aldehyde
al
oxo / formyl
!C! || O
Ketone
one
Oxo/Keto
OH
Alcohol
ol
Hydroxy
oate (alkyl+w.r.+oate) Alkoxy carbonyl
|| O
(7)
–
(8)
–
(9)
–
(10)
(11)
–
Nomenclature of Organic Compound
[21]
SH
Thio-alcohol
thiol
Mercapto
NH2
Amine
amine
Amino
(12)
–
(13)
–
(14)
(=)
ene
(15)
( % )
yne
Note : Double bond & triple bond are not true functional groups. w.r. # Word Root Rule for their nomenclature : (1) Selection of parent 'C' chain : longest possible 'C' chain with functional group and having maximum number of multiple bonds is selected as parent 'C' chain.
CH3 – CH2 – CH – CH2 – CH2 – CH3 | C OOH CH2 = CH – C H – CH2 – CH2 – CH3 | C OOH (2) (a) (b)
CH3 – CH2 – C – CH2 – CH – CH3 | || OH C H2
Numbering : Numbering starts from the side of functional group for numbering priority order is given below : Functional group > Multiple bonds > Substituents If chain ending 'C' containing functional group is present then numbering starts from the 'C' of functional group these functional groups are known as DON category functional groups functional groups of this catagoly are shown below : – COOH – CN !C!O!C! || || O O
CHO
–
COOR – CONH 2
COCl
–
–
Rule 3 : 'e' of primary suffix is dropped if secondary suffix starts from a vowel. Example of compounds having don catagory functional groups : (i) CH3 – CH2 – CH2 – COOH Butanoic acid
(ii)
(iii)
CH 3 ! CH ! CH 2 ! CH 3 | COOH
O || CH 3 ! CH 2 ! C ! CH 2 ! CH 2 ! C ! Cl || CH 2 O || C
(iv) H
2-methyl butanoic acid
4-ethyl pent-4-en-1-oylchloride
methanamide NH2
Nomenclature of Organic Compound
[22]
(v)
CHO | CHO
ethandial
(vi)
NC – CH2 – CH2 – CH3
butane nitrile
(vii)
(viii)
O || H2N – C – CH2 – CH – CH2 – CH = CH2 | CH || CH2 O || CH2 = CH – CH – C – Cl | Cl – H2C – H2C – CH2
3-ethenyl hex-5-en-1-amide
2-(3-chloropropyl) but-3-en-1-oyl chloride
O || R – C – O – R
Ester :
alkanoate # alkyl alkanoate
alkyl
e.g.
(i)
(ii)
(iii)
O || CH3 – C – O – CH3 O || H – C – O – CH 3 – CH3 O || CH3 – CH – CH2 – C – O – CH3 | CH2 – Cl
Methyl ethanoate
ethyl methanoate
methyl-4-chloro-3-methyl butanoate
(iv)
O || Cl – CH2 – O – C – CH3
chloromethylethanoate
(v)
H3COOCCH 3
methyl ethanoate
Nomenclature of Organic Compound
[23]
O ||
C H 2 ! C ! O ! CH 3
(vi)
|
methyl-2-ethyl butane-1, 4-dioate.
H 3C ! H 2 C ! CH ! C ! O ! CH 3 ||
O Anhydride : Nomenclature of anhydride is done on the basis of the carboxylic acid from which it is obtained.
O || CH3 – C – O H + CH3 – C – OH || O
– H2O
H2O O
H3C – CH2 – C || O ethanoic propanoic anhydride O || CH2 – C | CH – 2 C || O
O
CH3 – C || O ethanoic anhydride
ethanoic acid O || CH3 – C
O || CH3 – C
O || CH3 – C – O H + CH3 – CH2 – C – OH || O
butanedioic anhydride
O
O C
Benzene carboxylic propanoic anhydride
O C O O C O
Benzene carboxylic-3-phenyl propanoic anhydride
C O
Nomenclature of Organic Compound
[24]
O C
Benzene carboxylic anhydride O
C O
O C Benzene carboxylic cycloh carbocyclic anhydride
O C O
Example of compounds having functional group other than DON category :
OH |
1.
H 3C ! CH 2 ! CH 2 ! C H ! C H ! CH 3
(3 – propylheptan – 2 – ol)
|
H 3C ! CH 2 ! CH 2 ! CH 2
2.
3.
4.
5.
OH | CH2= CH – CH2 – CH – CH – CH3 | H3C – H2C – H2C – CH2
SH | H3C – C – C – CH2 – CH3 || CH2 Me | CH2 – CH – SO3H | CH2 – CH – SO3H | Et
3 – butyl hex – 5 – en – 2 – ol
2 – methylpent – l – ene – 3 – thiol
heptane – 2, 5 – disulphonic acid
O || CH3 – CH = CH – C – CH2 – C – CH2 – CH3 || CH2
5 – methylene oct – 6-en – 3 – one
Nomenclature of Organic Compound
[25]
6.
3 – (1 – methyl butyl) pent – 3-ene – 1 – sulphonic acid
SO3H
3 – ethylhexan – 2 – amine
7. NH2
8.
CH3 – CH2 – CH – CH2 – CH3 | NH – CH2 – CH3
N – Chloromethyl – N – methyl pentan – 2 – amine
N
9.
N – ethyl pentan – 3 – amine
Cl POLYFUNCTIONAL COMPOUNDS
Rule-I : If more than one functional groups are present then one is selected as principal functional group and represented by suffix. Other functional groups are treated as substituents & representated by prefix.
Selection of principal functional group is done according to priority table O ||
1.
HS ! CH 2 ! C H ! C ! OH (3 – mercapto – 2 – methylpropanoic acid) |
CH 3 O ||
chloromethanoylchloride
2. Cl
Cl O ||
amino methanomide (Urea)
3. H2N
CN
NH2 CN 2 – ethenyl – 2 – isocyano propane – 1,3 – dinitrite
4. CN
Nomenclature of Organic Compound
[26]
O 3 – oxo pentanal
5. O O 6.
2-hydroxy-3-oxo pentanoic acid
HO
OH O
O 7.
NH2 NH2
2 – amino ethanomide
Rule-II : When principal group is selected then there is no use of priority table.
8.
COOH | H – C – OH | H – C – NH2 | COOH
3 – amino – 2 – hydroxy butane – 1, 4 – dioic acid
(Incorrect)
2 – amino – 3 – hydroxybutane – 1, 4 – dioic acid (Correct)
Rule-III : If any DON functional group is present as sec. functional group then its 'c' is not included in principal 'c' chain except – CHO group.
9.
10.
O || NC – H2C – H2C – C – OH O || CH2 – C – OH | CH2 – C – Cl || O H2N O
3-Chloro carbonylpropanoic acid
11.
Carbamoyl methanoyl chloride O
Cl
12.
3 – cyanopropanoic acid
H 2N
3-Ethylpent-4-yn-1-amide
|| O
Rule-IV : As secondary functional group, if 'C' of – CHO group is included in parcent 'c' chain then oxo is used as prefix, otherwise we use formyl group as prefix. O
13.
||
O ||
H ! C ! CH 2 ! CH 2 ! C ! OH
4 – oxobutanoic acid
Nomenclature of Organic Compound
[27]
14.
15.
O || H – C – CH2 – CONH2 | CH2 – CONH2
2 – formyl butane – 1, 4 – diamide
O O O || || || Cl – C – CH2 – C – CH2 – C – H
3, 5 – dioxopentanoyl chloride
IUPAC nomenclature if DON category functional group is present as principal functional group & its 'c' is not included in parent 'c' chain
COOH
Carboxylic acid
–
– C – O – C – || || O O – COOR – COCl – CONH 2 – CN – CHO
Carboxylic anhydride Carboxylate Carbonyl chloride Carboxamide Carbonitrile Carbaldehyde
e.g.
COOH 1.
Cyclohexane carboxylic acid COOH
2.
3.
4.
Benzene carboxylic acid CH2 – CHO | CH2 – CHO | CH2 – CHO
Propane – 1, 2, 3 – tricarbadehyde
CH2 – COOH | CH – CH2 – COOH | CH2 – COOH
3 – Carboxymethyl pentane – 1, 5 – dioic acid
O || C
5.
O C || O
Cyclohexane-1, 2 – dicarboxylic anhydride
Nomenclature of Organic Compound
[28]
NOMENCLATURE OF ALICYCLIC COMPOUNDS
(A)
Unsubstituted cyclo compounds :
Example :
(B)
Prefix + word root + suffix Cyclo + no. of C + ane / ene
Cyclobutane
Cyclopropane
Cyclohexene
Substituted cyclic compound (closed + open chain saturated) Rule : If number of carbons in closed chain - no. of carbons in open staurated chain, then closed chain (i) will be selected as parent chain. 2
1
1
3
Example : 3
4
2
1-methyl cyclo propane 1
2
(Carbon of closed chain)
5
Propyl cyclo pentane
3
1-(2-methyl propyl) cyclohexane
(ii)
If number of carbons in open chain > closed chain . Open chain is parent chain 3
1
4
2
5 6
2-cyclopentyl-4-methyl hexane 2 1
3
1 5 4
4
1-ethyl-2-methyl cyclobutane
2 3
3-ethyl-1,1-dimethyl cyclopentane
Rule : Cyclic compounds with functional group is considered as parent chain :
(i)
Nomenclature of Organic Compound
[29]
2 1 CH2COOH Cyclohexyl ethanoic acid
# If FG ( – COOH) present on both cylcic and non-cyclic then number of carbon atoms is considered.
cyclopentyl cyclohexane
If unsaturation (Multiple bond) present Rule : Chain containing multiple bond is selected as parent chain 1
1 3
3
2
1 2
2 3-butyl cyclopropene
1-cyclopentyl eth-1-ene
3-cyclopentyl but – 1 – ene
If ring and non-cyclic side chain both containing double bond then check the nunbmer of C atoms and given parent chain. 4
1'
3'
3
5
2'
1
2
3-(prop-2-enyl) cyclo pent-1-ene
Number of duble bond is considered while selecting parent chain 5' 1'
4'
3
1 2
3'
4
2'
1-(cyclopent-2-enyl) buta-1,3-diene In case of more than one multiple bond use suffix ‘a’ after word root. 3 2 1
4 5
6 5-propyl cyclohexa-1, 3-diene
Nomenclature of Organic Compound
[30]
O – C O (Parent chain)
Cyclobutyl cyclohexane carboxylate O O – C – CH2CH3
Cyclohexyl ethane carboxylate
– C – NH2
Carboxamide
O O
eg.
C – NH2
eg.
NH – C – CH3
Cyclohexane carboxamide
N – Cyclohexyl ethanamide
O
4
5 3 – Cyclohexyl cyclopentanol
3 2
1 OH
Methylene cyclohexane
NOMENCLATURE
OF BICYCLO COMPOUNDS
Bicyclo compounds : If two rings are fused at two common carbon atoms then compound are known as bicyclic compound. Bridge head Bridge Bridge *
*
*
*
Bridge head Two common carbon
(i)
Bridge
Bridge should be present
Unsubstituted bicyclo compounds
Prefix Bicyclo
+
Numbering of carbon atoms in each bridge in decreasing order
+
Nomenclature of Organic Compound
Suffix
[31]
Biyclo (4.4.0) decane (Bridge head C not considered)
Bicyclo [2.2.0] Hexane
eg.
Bicyclo [2.1.1] Hexane
Bicyclo [3.2.0] Heptane
eg. (ii)
eg.
Substituted bicyclo (Bicyclo with subtitution or functional group) In substituted bicyclic compounds numbering starts from a bridge head carbon atom and proceeds towards longest bridge then smaller bridge & then smallest bridge. 1
2 Cl
6 7 5
2 – Chloro bicylo [2.2.1] heptane
3
4
1 2
eg. 3
6
O C H O
7
bicylo [2.2.1] heptane – 7 – carboxylic acid
5
4
1
eg. 5
2
Bicyclo [2.1.1] hexane
6
3 4 1 2 3
5 HOOC
6
Bicyclo [2.1.1] hexane – 5 – carboxylic acid
4 5 HOOC
6
4 3
9
2 8
7
F.G. is preffered over do uble bond. Bicyclo [3.2.2] dec – 9 – en – carboxylic acid
1 Bicyclo [3.2.2] non – 8 – ene – 6 – carboxylic acid
Nomenclature of Organic Compound
[32]
