This document discusses the nomenclature of bridged cycloalkanes, heterocyclic compounds, and fused ring systems. It begins by explaining the nomenclature rules for bicyclo and tricyclo compounds using the SBSTPF and STSTPF systems respectively. It then discusses spiro and bridged heterocyclic compounds. The document provides numerous examples of applying these nomenclature rules. It also discusses the nomenclature of monoheterocyclic, fused heterocyclic, and heterocyclic compounds fused with benzene rings using appropriate prefixes and suffixes.

1. Nomenclature of Bridged cycloalkanes and Heterocyclic
Compound
Dr. Anshu Dudhe
(Professor)
Nagpur college of pharmacy, Nagpur

2. BRIDGED CYCLOALKANES
Bicyclo compound: Bicyclo compounds are compound
which contain two fused ring. The Carbon atom where
Two rings are Fused are called Bridge Head Carbon and
remaining other Carbons are called bridge carbon.
Bridge Head Carbon
Bridge Head Carbon
Bridge Carbon
Bridge Carbon
Norborane
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

3. NOMENCLATURE OF BICYCLO
COMPOUND (SBSTPF)
Substituent (S)
Bicyclo (B)
Square bracket containg bridge Carbon in Decreasing order (S)
Total no. Carbon in principal Chain ( Eth, Prop, But) T
Primary Suffix (ane, ene, yne, Diene) (P)
Functional Group (F)
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

4. EXAMPLES
Largest Ring is preferred over Smallest ring. So
Numbering Start from Bridge head Carbon and Cover
Largest ring first
1
2
3
4
Rule: SBSTPF
Substituent: NIL
Bicyclo : Bicyclo
Square Bracket: [1.1]
Total No of Carbon : 4 ( but)
Primary Suffix : ane
Function Group: NIL
IUPAC Name: Bicyclo[1.1]butane
Rule: SBSTPF
Substituent: NIL
Bicyclo : Bicyclo
Square Bracket: [4.2.0]
Total No of Carbon : 8 (oct)
Primary Suffix : ane
Function Group: NIL
IUPAC Name: Bicyclo[4.2.0]octane
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

5. EXAMPLES
CH3
CH3
1 2
3
4
5
6
7
8
9
Rule: SBSTPF
Substituent: Methyl Group
Bicyclo : Bicyclo
Square Bracket containing Bridge Carbon : [3.3.1]
Total No of Carbon containing Bridge carbon : 9 (Non)
Primary Suffix : ane
Function Group: NIL
IUPAC Name: 1,3-DimethylBicyclo[3.3.1]nonane
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

6. EXAMPLES
Rule: SBSTPF
Ring Substituent: Nitrogen (aza), Oxygen (Oxa)
Bicyclo : Bicyclo
Square Bracket containing Bridge Carbon : [3.2.0]
Total No of Carbon containing Bridge carbon : 7
(Hept)
Primary Suffix : ane
Function Group: Ketone (suffix: one)
IUPAC Name: 4-oxa-1-azaBicyclo[3.2.0]heptane
N
O
O 1 2
3
4
5
6
7
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

7. EXAMPLES
N
O
S
1
2
3
4
5
6
7
8
Rule: SBSTPF
Ring Substituent: Nitrogen (aza), Sulphur (Thia)
Bicyclo : Bicyclo
Square Bracket containing Bridge Carbon : [4.2.0]
Total No of Carbon containing Bridge carbon : 8 (Oct)
Primary Suffix : ane
Function Group: Ketone (suffix: one)
IUPAC Name: 5-Thia-1-azaBicyclo[4.2.0]octan-8-one
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

8. TRICYCLO COMPOUND
Tricyclo compounds are chemical compounds that
contain three fused rings of atoms.
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

9. NOMENCLATURE OF
TRICYCLO COMPOUND
(STSTPF)
Substituent (S)
Tricyclo (T)
Square bracket containg bridge Carbon in Decreasing order (S)
Total no. Carbon in principal Chain ( Eth, Prop, But) T
Primary Suffix (ane, ene, yne, Diene) (P)
Functional Group (F)
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

10. EXAMPLES
Rule: STSTPF
Substituent: NIL
Bicyclo : Tricyclo
Square Bracket containing Bridge Carbon : [2.2.1.0]
Total No of Carbon containing Bridge carbon : 7 (hept)
Primary Suffix : ane
Function Group: NIL
IUPAC Name: Tricyclo[2.2.1.0]heptane
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

11. EXAMPLES Br
1 2
3
4
5
6
7
8
9
Rule: STSTPF
Substituent: Bromo
Bicyclo : Tricyclo
Square Bracket containing Bridge Carbon : [3.2.2.0]
Total No of Carbon containing Bridge carbon : 9 (non)
Primary Suffix : ane
Function Group: NIL
IUPAC Name: 2-BromoTricyclo[3.2.2.0]heptane
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

12. SPIRO COMPOUNDS
Spiro compound are chemical compound in which two
rings are fused with Single Carbon atom.
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

13. NOMENCLATURE OF SPIRO
COMPOUND (STSTPF)
Substituent (S)
Spiro (S)
Square bracket containing bridge Carbon in Increasing order
(S)
Total no. Carbon in principal Chain ( Eth, Prop, But)(T)
Primary Suffix (ane, ene, yne, Diene) (P)
Functional Group (F)
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

14. Numbering start from one carbon away than
Spiro Carbon . Smallest ring is preferred over
largest ring.
4
5
6
7
8 9
1
2
3
Rule: SSSTPF
Substituent: NIL
Bicyclo : Spiro
Square Bracket containing Bridge Carbon : [3.5]
Total No of Carbon containing Bridge carbon : 9 (non)
Primary Suffix : ane
Function Group: NIL
IUPAC Name: spiro[3.5]nonane
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

15. EXAMPLES
4
5
6
7
8 9
3
2
CH3
1
Rule: SSSTPF
Substituent: Methyl
Bicyclo : Spiro
Square Bracket containing Bridge Carbon : [3.5]
Total No of Carbon containing Bridge carbon : 9 (non)
Primary Suffix : ane
Function Group: NIL
IUPAC Name: 1-methyl spiro[3.5] nonane
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

16. EXAMPLES
1
2
3
5
6
8
9 10
7 4
Rule: SSSTPF
Substituent: NIL
Bicyclo : Spiro
Square Bracket containing Bridge Carbon : [4.5]
Total No of Carbon containing Bridge carbon : 10 (dec)
Primary Suffix : diene
Function Group: NIL
IUPAC Name: 1-methyl spiro[4.5]dec-1,6-diene
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

17. NOMENCLATURE OF
HETEROCYCLIC COMPOUND
Heterocyclic compound are Chemical compound which
contain heteroatom (o, N, S) in cyclic ring.
e.g.
O
Furan
Contain Oxygen Heteroatom
N
H
Pyrrole
Contain Nitrogen Heteroatom
S
Thiophene
Contain Sulphur Heteroatom
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

18. NOMENCLATURE OF
MONOHETEROCYCLICS
The priority order of hetero atoms is O, S, N, P, Si.
Heteroatom Prefix
Oxygen oxa
Nitrogen aza
Sulphur Thia
Phosphorous Phospha
Selenium Selena
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

19. NOMENCLATURE OF HETERO
MONOCYCLICS
The size of heterocyclic ring is indicated by suffix.
Trick to learn : Iretol, an Tablet kept on Box called epoc,
and box placed on ecu (electric Control Unit). NOW it
becomes
Ir :3 membered ring
Et: 4 membered ring
Ol: 5 membered ring
in: 6 membered ring
ep: 7 membered ring
oc :8 membered ring
on: 9 membered ring
ec :10 membered ring
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

20. Ring Size Suffix Saturated Unsaturate
d
Saturated
( with
Nitrogen
3 Ir Irane irine iridine
4 Et Etane ete etidine
5 Ol Olane ole olidine
6 In Inane ine
7 Ep Epane epine
8 Oc Ocane ocine
9 On Onane onine
10 Ec Ecane ecine
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

21. RULE: PREFIX + SUFFIX
O
oxa +irane=Oxirane
Prefix for Oxygen: oxa
Suffix for 3 membered Saturated ring :Irane
Now add Prefix and Suffix but skip terminal a of
prefix while writing Nomenclature
H
N
Aza + iridine =Aziridine
Prefix of Nitrogen: aza
Suffix for 3 membered Saturated ring with Nitrogen :iridine
Now add Prefix and Suffix but skip terminal a of
prefix while writing Nomenclature
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

22. EXAMPLES
S
Thia +irane=Thirane
Prefix of Sulphur: Thia
Suffix for 3 membered Saturated ring :irane
Now add Prefix and Suffix but skip terminal a of
prefix while writing Nomenclature
Oxa +etane= Oxetane
Prefix of Oxygen:Oxa
Suffix for 4 membered Saturated ring :etane
Now add Prefix and Suffix but skip terminal a of
prefix while writing Nomenclature
O
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

23. EXAMPLES
Prefix of Sulphur :Thia
Suffix for 5 membered Saturated ring :olane
Now add Prefix and Suffix but skip terminal a of
prefix while writing Nomenclature
S
Thia+olane=Thiolane
N
H
Aza + inane = Azinane
Prefix of Nitrogen :aza
Suffix for 6 membered Saturated ring :Inane
Now add Prefix and Suffix but skip terminal a of
prefix while writing Nomenclature
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

24. EXAMPLES
When two or more different hetero atoms are present in the same ring, the prefixes of
hetero atoms are combined in the order of preference O, S, N, P, Si. Numbering
start in such a way that heteroatom will get lowest value.
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

25. NOMENCLATURE OF
HETEROCYCLIC RING FUSED
WITH BENZENE RING
Benzene ring is considered as Prefix and named as Benzo
and Heterocyclic ring is used as Suffix. Both Suffix and
Prefix are connected by Fused Letter in Square Bracket.
Prefix[Fusion Letter]Suffix
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

26. EXAMPLES
O
Benzo [b] furan
or Benzofuran
1
2
3
4
5
6
7
a
b
N
1
2
3
4
5
6
7
8
a
b
Benzo[b]pyridine
or Quinoline
S
1
2
3
4
5
6 7
a
b
c
Benzo[c]thiophene
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

27. NOMENCLATURE OF HETEROCYCLIC FUSED WITH
OTHER HETEROCYCLIC
Rules:
1. Name of minor ring or prefix [fusion number, fusion no. letter] name of
major ring or Suffix.
2Divide two rings. Numbered each Ring Individually.
3.Fusion letter comes from major ring and fusion no comes from minor ring.
4.Priority order: N, F, Cl, Br, I, O, S, Se (Heteroatom Nitrogen is preferred
over O or S).
5. A heterocyclic ring containing largest ring is preferred over smallest ring .
6. A heterocyclic ring containing greater no. of heteroatom and greater
variety of heteroatom is preferred
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

28. 7. A heterocyclic ring containing heteroatom with lower locants
(position) is more preferred.
8. If a position of fusion is occupied by a heteroatom in the fused
heterocyclic compound. Heteroatom is common for both rings
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

29. EXAMPLES
O
O
O
Considered as Major Ring because
large ring is preferred over small Ring
having simillar heteroatom
O
1
2
3
4
5
4
1
5
4
3
2
2H-Furo[3,2-b]pyran
1
2
3
4
5
6
7
a
b
Divide fused ring in to individual Ring.
Fusion letter comes from major ring and
fusion no comes from minor ring
Considered as Minor Ring due to small Ring
size.Fusion No. will be done according to Direction of
Major ring.
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

30. EXAMPLES
C o n s i d e r e d a s M a j o r R i n g
d u e t o g r e a t e r v a r i e t y
D i v i d e f u s e d r i n g i n t o i n d i v i d u a l R i n g . F u s i o n
l e t t e r c o m e s f r o m m a j o r r i n g a n d f u s i o n n o c o m e s
f r o m m i n o r r i n g
N
O
N
1
2
3
4
5
6
7
8
5 H - P y r i d o [ 2 , 3 - d ] o x a z i n e
a
b c
d
N
O
N
C o n s i d e r e d a s M i n o r R i n g d u e t o l e s s e r
v a r i e t y
1
2
3
1
2
3
4
5
6 4
5
6
a
b
c
d
e
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

31. EXAMPLES
N
N
N
N
Pyrazino[2,3-d]pyridazine
N
N
N
N
1
2
3
4
5
6
a
b c
d
1
2
3
4
5
6
Considered as M inor Ring due to greater Locant
Position.Fusion No. will be calculated according
to Direction of M ajor ring.
Considered as M ajor Ring due to Lower
Locant position.
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR

32. EXAMPLES
S
N
N
1
2
3 a
b
Im idazo[2,1-b]thiazole
N
H
N
N
S
C onsidered as M ajor R ing due to greater variety.
C onsidered as M inor R ing due to
lesser variety
F usion N o. w ill be done according to
D irection of M ajor ring.
D ivide M olecule into tw o parts and com m on
atom is P art of both ring
1
2
3
4
5
a
b
c
d
1
2
3
4
5
DR. ANSHU RUPESH DUDHE, NAGPUR COLLEGE OF PHARMACY, NAGPUR