nomenclature.pdf

IIT-JEE ChEmistry by N.J. sir

ORGANIC chemistry

NOMENCLATURE Rule-1 Select the longest chain Q.2

Q.4

Q.5

Q.3

R

Q.1

Rule-2 If 2-chains are same lengths select chain with more number of branches. Q.2

Rule-3 General formula

Q.3

SI

Q.1

Prefix(s) + Word Root + Suffix (P) + Suffix (s)

N.

J.

1.

Word Root :- Represents Number of carbon atoms in main chain. No. of Carbon atoms Word Root0…….. 1 meth 2 eth 3 prop 4 but 5 pent 6 hex 7 hept 8 oct 9 non 10 dec 11 undec 12 dodec 13 tridec 14 tetradec 15 pentadec 16 hexadec 17 heptadec 18 octadec 19 nonadec 20 eicos 30 tricont

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1

Rule-4 Side chains are represented as alkyl group CnH2n+1  alkyl CH3—- methyl (Me) CH3 — CH2 — Ethyl (Et) CH3 — CH2 — CH2— propyl (pr) CH3 — CH2 — CH2 — CH2 — butyl (bu) (1-methyl ethyl)

CH3 — CH — CH2 — | CH3

(2-methypropyl)

SI

R

CH3 — CH — | CH3

CH3 | CH3 — C — | CH3

(2,2,-dimethyl ethyl)

Rule-5 Alkyl groups are used as prefixes

2 1

J.

Rule-6 Numbering should be done such that 1st locant gets lowest possible number. 6

4

3

6

5

(Correct) 2

1

3

4

1

2

3

6 5

(Correct)

7

4

6 7

5

3

1

(Incorrect)

6

5

6

4

N. 1

2

4

2

(Incorrect)

4

3

5

7

7

2

3

5

(Incorrect) 3-methyl 5-ethyl

1

(Correct) 3-ethyl 5-methyl

Rule-6

If first locant same then look for sum rule:1

4

2 3

2 + 5 + 6 = 13 Higher sum Incorrect

6 5

7

6 7

4 5

2 3

1

2 + 3 + 6 = 11 lower sum Correct


2

2

4

8

6 1

5

3

8

7

3 + 5 + 6 = 14 Incorrect

5

7

4

6

1

3 2

3 + 4 + 6 = 13 Correct

Rule-7 Suffix (P)  Primary suffix Alkane  ane Alkene  ene Alkyne  yne 5

R

1

3

6

2

4

SI

Prefix(s) + Word Root + Suffix (p) + Suffix (s) 3-methyl hexane Remember  Number, number Number – word, No gap between 2 letters

Rule-8 Multiple substituents are represented as di, tri, tetra, penta etc. 5 3

6

4

5

1

6

2

2,3-dimethyl hexane

4

1

3

2

2,3, 4-trimethyl hexane

6 7

J.

Rule-9 Prefixes are arranged in alphabetical order

5

4

3

2

5

7

1

4

6

3

1

2

4-ethyl-2, 3-dimethylheptane 3,5-diethyl-4-methylheptane di, tri etc. are not considered for arranging in alphabetical order Complex Substituent:For multiple substituents bis, tris, tetrakis, pentakis are used.

N.

Rule-10

7

5

4

6

1

3

2

4-(1-methylethyl)heptane 7

9

5 8

6

7 8

6

1

3

5 4

2

4,5-bis-(1-methylethyl)nonane

1

3 4

9

2

4,5-bis-(1-methylpropyl)nonane


3

Practice questions:

Q.2

Q.3

Q.4

Q.5

Q.6

Q.7

Q.8

R

Q.1

SI

Q.9

Nomenclature or Spiro Compound::



only one common carbon between 2 cyclic rings

Numbering will be done from neighbouring position of common carbon. 7

6

8

9

1

2

4

3



J.

5

General formula Spiro (x.y) + word root + Suffix(p) + Suffix(s)

X  Y  Numbering is done in increasing order 1

5

6

4

Spiro [3.4] octane

7

N.

2

8

3

5

1

Q.1

2

Q.2

7

1

6

Q.3

Q.4

8

9

4

3

1,2,3 – trimethylspiro[4.4] nonane

8

3

7

6,7 – dimethylspiro[3.4] octane 8

1

2

5

6

4

2

7

8

3

5 – methylspiro[3.4]octane

5

1

6

4

2

7

4 3

5

6

5 – methylspiro[3.4] octane


4

5

1

Q.5

2

6

6

7

8

8

9

Spiro [3.4] oct – 6 – ene

2

1

Q.6

4 3

7

5 3

4

2 – (1-methylethyl)spiro[4.4]nonane

Q.7

Q.2

R

Q.1

SI

Nomenclature of Bicyclo compound :

Bridge positions

Prefix(s) + bicyclo [x.y.z.] + word root + suffix (p) + suffix (s)

XYZ  

Numbering is done from bridge head postion Numbering is done in decreasing order of carbon atoms (2)

(3)

(4)

(5)

(8)

(9)

(10)

(2) (4)

bicyclo [2.2.1] heptane 7 – methylbicyclo [2.2.1] heptane

J.

(1)

(6)

(7)

bicyclo [2.2.2] octane bicyclo [1.1.0] butane

N.

Ans:- (1) (3)

Nomenclature of alkens:  Select chains such that = is included in main chain 

Q.1

If more than one = are present, maximum double bonds should be included. 4

6

2

3

5

1

3–methyl hex–1–ene

Q.2

4

6

3

5 2

1

3–ethyl hex–1–ene


5

4

6

Q.3

4

5

Q.4

3 2

3

1



5

2

1

3–ethyl –5–methylhex–1–ene

6

3–propylhexa–1, 5-diene

In case of diene, triene ………..the letter ‘a’ is placed after word root. 6

5 5

6

Q.5

Q.6

1

3

2 1

2

3,4-dipropyl hexa – 1, 4 – diene

7

4 3

R

4

4 – methylidene – 5 – propylhepta – 1,5 – diene

Ethylidene 6 5

7

2 4 1

3

SI

Methylidene (doubly bonded substituents are named as methyl + idene)

4 – ethenyl – 5 – propyl hepta – 1, 5 – diene

Q.1

J.

Nomenclature of alkynes:Suffix (p)  yne

4

3

5 4

2

Q.2

3

1

6

5

3 – propylhex – 1 – yne

N.

Pent – 1 – yne Q.4

H3C — C  C — CH2 — CH — CH3

Q.6

CH3 (CH3 — CH2)2 — CH.CH — (CH2 — CH3)2 1

2

3

2

5

1

2

1

Q.7

Q.3

4

5

Q.5

3

4

6 7

hepta – 1, 5 – diyne

H3C — C.C — CH — (Et)2

6

H2C = CH — CH2 — CH2 — C CH Hex – 1 – ene – 5 – yne X Hex – 1 – en – 5 – yne 

If ene and yne are present at same number alphabetical order is considered.

X  a,i,o,u,y Remember


6

7

Q.8

6

5

3

4

2

1

H3C — CH = CH — CH2 — CH2 — C CH Hept – 1 – yne – 5 – ene X Hept – 5 – ene – 15 – yne X Hept – 5 – en – 1 – yne  CH2 6

C — CH2 — C — CH = CH 2 5

4

3

2

1

Q.10

Q.11

4

6

8

3 – methylidenehex – 1 – en – 5 – yne

1 2

Octa – 1, 3, 5, 7 – tetraene

Q.12

R

HC

Q.9

3

5

7

Nomenclature of Functional group containing Compound

2. — SO3H

Name Carboxylic Acid

Sulphonic acid

3. O || —C

Anhydride

Oic anyhdride (Carboxylic anhydride)

J.

O —C || O 4. O || — C — OR 5. O || — C — Cl 6. — C — NH2 || O 7. — CN

Suffix(s) Oic acid (When Carbon included) Carboxylic acid (When Carbon is not included) Sulphonic acid

SI

 Functional group 1. O || — C — OH

Ester

9.

O

Sulpho

——

Alkyl…….Oate (carboxylate when carbon not included) Oyl chloride (Carbonyl Chloride)

Alkoxy Carbonyl

Amide

Amide (Carbamide)

Carbamoyl

Cyanide

Nitrile (Carbonitrile)

Cyano

Isocyanide

Carbylamine

Isocyano

Aldehyde

al (Carbaldehyde)

Formyl

Ketone

One

Keto/oxo

Alcohol

Ol

Hydroxyl

Acid halide

N. 8. — NC

Prefix Carboxy

haloformyl

—C H O || —C— 11. — OH 10.


7

12. — SH 13. — NH2 14. —C=C

Thiol Amine Alkene

Thiol Amine —

Mercapto Amino (ene) Sufffix(p)

15. — C  C — 16. — NO2 — NO —F

Alkyne — — —

— — — —

(Yne) Suffix(p) Nitro Nitroso Fluoro

Nomenclature of Functional group containing Compound Functional group

R

 Name

— Cl

Prefix

—

Chloro

—

Bromo

SI

— Br

Suffix(s)

—I —O =N

Iodo

—

Epoxy

—

Diazo

—

Alkoxy

J.

— OR

—

Nomenclature of Alcohol:OH 1.

OH

2.

3. HO OH

N.

OH

4.

5.

6. Br

OH

Ans.

1. 3. 5.

hexan – 2 – ol 2. 2 – ethenylhex – 5 – enol 4. 5-bromocyclo hex – 2 – en – 1 – ol 6.

5 – propylhex – 5 – en – 2 – ol 3-ethyl-5-methylidene oct – 7 – en – 2 – ol 5-cyclohexyl cyclopent – 2- en – 1 – ol

O–H

H–O

Cl Q.1

O

Me

O

Q.2 H

Q.3 ON

Br


8

OH Q.4

OH

Br

Q.5

OH

Cl

Q.6

Br

Cl

OH

OH Q.7 OH

Ans.

1. 4-methoxy hexan-2-ol 3. 3,5-dicyclo propyl hexan-1-ol

2. 3-bromo-2-chloro-4-nitrosocyclopentan-1-ol

R

Cl

Nomenclature of carboxylic acid: If carbon included in main chain Suffix (s)  Oic acid



If carbon non included in main chain Suffix (s)  Carboxylic acid

O 1.

H3C — CH2 — C — OH 3

1

2

SI





propane-1-oic acid

X

propan-1-oic acid



2.

J.

O

3

4

H3C — CH — CH 2 — C — OH 1

2



3-methylbutane-1-oic acid

X

3-methylbutanss-1-oic acid



CH3

2

O

C — OH

1

N.

3

3.

4

6



cyclohexane-1-carboxylic acid (correct new) 



1-cyclohexylmethan-1-oic acid (old)



2-cyclohexylethan-1-oic acid

5

2

1

CH2 — COOH

4.

COOH 5.



cyclohexane-1,3-dicarboxylic acid

COOH


9

Q.

2

1

H3C

3

CH

CH2

COOH COOH COOH Propane-1, 2, 3-tricarboxylic acid (New) COOH 1 6

CH2—COOH

2

Q.

3

5 4

COOH

HOOC Q.

SI

COOH Cyclohexane 1, 3, 5-tricarboxylic acid 1 2

6

Q.

COOH

7 3

5

R

COOH 2-carboxymethyl cyclohexane-1, 4 dicarboxylic acid

4

Bicyclo [2.2.1] heptane-2-carboxylic acid 1 2

4

COOH

J.

Q.

3

Bicyclo [1.1.0] butane-2 carboxylic acid 7

2

6

4

COOH

N.

Q.

1

5

3

Spiro [.3] heptane-2-carboxylic acid

Nomenclature of aldehyde:O C—H

al



suffix(s)

O

H 1. Ans.

C

H

Methan-1-al O

O H

(1) 2,4,5 trimethyl hexan-1-al

2.

H

(2) Octa-3,5,7-trien-1-al


10

O O

O

Cl Q.

C

Q.

H

C—H

H

Q. C—H

Br

O H2 C Q.

CH2

H—C

H2 C

C—H

O

Q.

CH2

C

C O

O

CH

C

H O

H O

H

CHO

Q.

R

CHO CHO Q.

Nomenclature of ketones:O (1) propane-2-one

SI

CHO O

(2)

butan-2-one

O

(3)

(4)

O Cl

O

(5)

(7) Br

Nomenclature of cyclic ethers:H2C — CH2 1,2-epoxyethane (1)

(2)

Cl

O

H2C — CH — CH 2 1,2-epoxypropane O

N.

O (3)

O

(8)

J.

(6)

O

(4)

O

O

(5)

(6) O

O

Nomenclature of sulphonic acid:— SO3H group. SO3H (1)

cyclohexanesulphonic acid

5

(2)

3 2

4

6

1

hexane-2-sulphonic acid

SO3H 3

(3)

1 2

4

butane-1-sulphonic acid

SO3H


11

Nomenclature of Isocyanide (–NC): C (1) H3C — CH2 — N  ethan-1-carbylamine NC (2)

cyclohexane-1-carbylamine

3

5

1 2

(3)

4

pentan-2-carbylamine

NC

R

O 1 C–OH 4

2

(4)

2-ethyl-3-isocyanobutan-1-oic acid

3

3

5

(5)

1 2

4

SO3H

NC

Nomenclature of thiol. (— SH):SH (1)

SI

NC

4-isocyanopentane-1-sulphonic acid

cyclohexanethiol 3

1

J.

5

2

(2) 4

SH

6

1

5

(3)

pentane-2-thiol

SH

4-methylcyclohexane-1-thiol

2

N.

4

3

(4)

SH

8

3

7

4

2

1

7-merceptospiro [3.4] heptan-6-Ol

5

6

OH

OH

(5)

SH

(6) Br

SH OH

Cl

SH

SH (7)

SH

Cl

OH

(8)


12

Nomenclature of compounds containing multiple functional group:O OH O ON : (1) (2)

Cl O–H

CH=CH2

Br

O

O

H

H C

C

(3)

O

(4)

HO–C O (1) 5-ethenyl-6-hydroxyheptan-2-one (3) 6-methyl-7-oxoheptan-1-oic acid

Q.1

H–O

H

5

3

O 6-formyloctan-1-oic acid O Q.3

OMe

C OH

Q.1 Q.2 Q.3 Q.4 Q.5

H3CO

NO

Cl

O

O

O

Q.4

O

HO

C

CH

CH = CH

CH

C

O–H

Br

Cl

OH

NH2 6-formyloctan-1-oic acid Methyl-3-bromo-4-chloro-2-nitroso-6-oxo-hex-4-enoate 4-hydroxy-3-methoxy-7-methyl-8-oxo-oct-5-enamide 2-bromo-5-chlorohex-3-ene-1,6-dioic acid 2-amino-3-hydroxyhexanamide

N.

Ans.

CH3

Q.2

J.

O H2 N

7

C–H

H2 N

Q.5

H

8

6

1

Br

O

C

4

2

R

O

(2) 3-bromo-4-chloro-7-nitroso-6-oxoheptan-1-oic acid (4) 2-propylheptan-1-al

SI

Ans.

Nomenclature of substituted Benzene:-

Benzene



Monosubstituted Benzene:CH3

Methyl benzene (Toluene)

O CH3

Methyl benzene (Anisole)


13

NO2

NH2

Amino benzene (Aniline) Br

Nitrobenzene OH

Bromobenzene

R

Disubstituted Benzene:Br

Hydroxybenzene (phenol)

Br

1,2-dibromobenzene (o-dibromobenzene)

SI

Br

1,3-dibromobenzene, [metadibromobenzne (m-dibromobenzene)] Br

Br

Br

J.

1,4-dibromobenzene, [paradibromobenzene (p-dibromobenzne)]

Cl

1-chloro-2, 4-dinitrobenzene, (4-chloro 1, 3-dinitrobenzne X)

O2N

NO2

NO2

2-chloro-1-methyl-4-nitrobenzne

N.

Cl

CH3 O Me

Cl

2-chloro-4-methylanisole

CH3

NH2

CH3 4-ethyl-2-methylaniline CH2–CH3


14

OH

3,4-dimethylphenol CH3 CH3 Write the structure of :(a) o-ethylanisole (c) 2,3-dibromo-1-phenylpentane O CH3 CH2–CH3 Ans.

(a)

(b) p-nitroaniline (d) 4-ethyl-1 flouro-2-nitrobenzene F NH2 Br

(b)

(c)

(d)

Br

NO2

Ph

CH2–CH3

SI

Cl

OH

Q.1

Q.2

Q.3

O

Ph

Ph

O

O

O

Q.5

Q.6

H

C

C — OH

J.

Q.4

NO2

R

Q.

Q.7

O

OH C

Q.8

CH3

N.

Common Name:-

Benzene

Napthalene

Anthracene

Phenanthrene

Common Name H3C — CH —

I.U.P.A.C. 1-methyl ethyl

Common Isopropyl

CH3


15

H3C — CH — CH 2 —

2-methylbutyl

isobutyl

2,2-dimethylpropyl

Neopentyl

CH3 CH3 H3C — C — CH 2 — CH3 CH3 H3 C — C —

tert.-butyl

CH3 H3C — CH2 — CH —

sec.butyl

R

CH3

1. 2.

H3C — CH2 — NH2  NH2  NH2

3.

SI

Nomenclature of Amines:—NH2 Suffix(a)  Amine Prefix  Amino Ethanamine

3,4-dimethylpentanamine



5-bromocyclohex-3-enamine



2-bromobut-3-enamine



3-aminobutan-1-oic acid

Br 4. 4

5.

5

J.

NH2

Br

2

3

OH

1

NH2 O

Br

N.

Cl

NH2

Q.1

Q.2 NH2

Br

NH2

Q.3

OMe

NH2

Q.5.

NH2

Q.4

Cl

Cl NH2

Q.6


16

NH2

Cl

Q.7

Q.8

NH2

Cl

Q.1

Br Q.1 2-bromobut-3-enamine Q.2 3-bromo-5-chloro oct-7-enamine Q.3 6-methoxyoct-7-enamine Q.4 3-chloro-4,5-dimethyl hept-4-enamine Q.5 3-cyclopylpent-4-enamine Q.6 3-butyl-2-chloropent-4-enamine Q.7 4-bromo-5-chlorohex-2-enamine Q.8 3-chloro-5-ethyl-6-propyl oct-7-enamine CH3 N H N-methylaminopropane

R

Ans.

N — CH3

Q.2

N, N-dimethylaminobutane H3C

CH3 N

Q.3

SI

CH3

J.

N, N-dimethylaminobenzene Nomenclature of Esters:O

N.

R’ — C — OR  Alkyl  (Name starts with alkyl)

O

Q.1

H3C — CH2 — C — O — CH3

Br

Q.3

Q.2

Methylpropan-1-oate O

H2C — CH2 — C — O — CH3 Methyl-3-bromo-propan-1-oate

Q.4

O H3C — C — O — CH2 — CH2 — CH3 propylethan-1-oate O H3C — C — O — CH 2 — CH = CH 2 Prop-2-enylethanoate

O Q.5

O Cyclopropylbutanoate


17

O

O (1)

(2)

O

O

O

O Br

(3)

O — CH2 — CH3 (4)

O—Et Cl O

O

R

C — O — Me (5)

(6)

O

O

O

C — O — Me

(8)

Nomenclature of Anhydrides:-

H3C — CH2 — C — O Me

SI

(7)

O

O

O

C

O

R+H

O

H

J.

  

C R — C — OH + H — O — C — R  R O Formed by loss of H H Suffix(s) oic anhydride (If carbon included) Carboxylic anhydride (if carbon not included)

O

Naming of symmetrical Anhydrides:: O

H3C — C

ethanoic anhydride

O

N.

(1)

H3C — C

O

O

H3C — CH2 — C

(2)

propanoic anhydride

O

H3 C — H2C — C

O O H3C — CH2 — CH2 — C (3)

O butanoic anhydride H3C — H2C — H2C — C O


18

O (4)

butane-1,4-dioic anhydride

O O

Naming of Unsymmetrical anhydride:O O H3C — C — O — C — CH2 — CH3 Ethanoic propanoic anhydride O

O (2)

R

(1)

O

O (3)

O

SI

Butanoic-2-methylpropanoic anhydride

O Butanoic prop-2-enoicanhydride

O (4)

O O Butanoic propanoic anhydride

J.

Nomenclature of cyanides:Nitrile CN

Carbonitrile

H3C — C  N

Q.2

CN

Q.4

Q.5

CN

Q.3

CN

N.

Q.1

Br

Br CN Q.6

CN Cl

Br

Q.7

Q.8

CN

CN Ans.

Q.1 Q.4 Q.6 Q.8

ethanenitrile Q.2 butanenitrile 4-ethylpent-4-ene-1-nitrile 4,6-dibromo-5-chloropentane-nitrile 5-bromohex-3-ene-1-nitrile

Q.3 Q.5 Q.7

2,4,5-trimethylhexanenitrile 5-cyclopropylhepta-3,6-diene-1-nitrile 3-methylidenepent-4-one-1nitrile


19

CN

Q.1

H2C — CH — CH 2

Q.2

CN

NC

Q.3

CN

CNQ.4

Q.3

H2C — CH2 CN CN

CN

CH2—CH2—CN

Q.5 CN

CN

Nomenclature of Amides:O Methanamide

R

H — C — NH2

O (1)

(2)

NH2 (1) (2) (3)

NH2

pent-2-en-1-amide, pent-2-enamide 3-cyclopropyl pent-3-en-1-amide N-methylhexan-1-amide

N

Me H

O

O

(4)

O

(3)

SI

Ans.

O

Br

(5)

H3C — C — N

N

Me

N-Bromo-3-Ethyl-N-Methylpentanamide O

(7)

N

J.

(6)

N-Ethyl-N-Methylethanamide O Me N Pr

Me

O

N

Br

(8)

N

(9)

Br

O

N.

Nomenclature of Acid Halides:-

O

(1)

H3C — C — Cl

ethanoylchloride O

O

Cl

(2)

(3)

Cl

(4)

Cl

O


20

nomenclature.pdf

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