Organic Chemistry: Nomenclature Summary
IUPAC SYSTEM OF NAMING COMPOUNDS
1. Select the longest continuous chain of carbon atoms
for the basic name.
2. Number the carbons in the chain from the end nearest
the first branch (to give lowest set of numbers).
3. Identify substituents. If more than one substituent of
the same kind is present, use the prefixes “di”, “tri”,
“tetra”.
4. Locate the substituents by the number of the carbon
to which they are attached.
5. Put substituents in alphabetical order (multiplier
prefixes do not count).
6. Separate numbers from letters by a dash and write the
whole name as one word with the basic name at the
end.
IUPAC SYSTEM OF NAMING ALKENES
1. Select the longest continuous chain of carbon atoms
which contains both carbons of the double bond for
the basic name.
2. Change the ending to –ene from the –ane of the
corresponding alkane
3. Number the carbon atoms in the chain from the end
nearest the first carbon of the double bond.
4. Locate the position of the double bond by the number
of the first carbon involved in the double bond.
5. Name substituents as with alkanes
6. In cyclic system number the carbons of the double
bond as 1 and 2.
IUPAC SYSTEM OF NAMING CARBOXYLIC ACIDS
Select the longest continuous chain of carbon atoms
which contains the carbon bearing the carboxylic
group.
2. Change the ending to –oic from the –ane of the
corresponding alkane.
3. The carboxylic carbon atom is assigned number 1.
4. Locate and name substituents as with alkanes.
SUBSTITUENTS
1.
2.
3.
4.
5.
F-
fluoro
Cl-
chloro
Br-
bromo
I-
iodo
IUPAC SYSTEM OF NAMING ALKYNES
Select the longest continuous chain of carbon atoms
which contains both carbons of the triple bond for the
basic name.
Change the ending to –yne from the –ane of the
corresponding alkane.
Number the carbons in the chain from the end nearest
the first carbon of the triple bond.
Locate the position of the triple bond by the number of
the first carbon involved in the triple bond.
Name substituents as with alkanes.
CARBOXYLIC ACIDS (cont’d)
1.
1.
2.
3.
4.
5.
6.
IUPAC SYSTEM OF NAMING ALCOHOLS
Select the longest continuous chain of carbon atoms
which contains the carbon bearing the hydroxyl group.
Change the ending to –ol from the –ane of the
corresponding alkane.
Number the carbons in the chain from the end nearest
the carbon bearing the –OH.
Locate the position of the –OH by the number of the
carbon to which it is attached.
Name substituents as with alkanes.
Hydroxyl (-OH) groups have priority over double bonds
in terms of numbering.
ESTERS
Nomenclature:
alkyl of alcohol part + alkyl of carboxylic acid part + oate
carboxylic acid
alcohol