Nomenclature of Saturated Hydrocarbons

IUPAC

International Union of Pure and Applied Chemistry

Alkanes and Cycloalkanes

belong to the family of saturated hydrocarbons

Alkanes and Cycloalkanes

molecules containing elements carbon and hydrogen connected by single bonds only

IUPAC Nomenclature

based on naming a molecule’s longest chain of carbon atoms connected by single bonds, whether in continuous chain or in a ring

Prefix

includes the kind and position of the substituents coming off the main chain

Parent

is the main chain

Parent Chain

the longest continuous chain of carbon atoms present in the molecule

Substituents

Groups that are not part of the longest chain are referred to as the branches or

Suffix

is the family

meth

methane = 1

eth

ethane = 2

prop

propane = 3

but

butane = 4

pent

pentane = 5

hex

hexane = 6

hept

heptane = 7

oct

octane = 8

non

nonane = 9

dec

decane = 10

undec

undecane = 11

dodec

dodecane = 12

tridec

tridecane = 13

tertradec

tertradecane = 14

pentadec

pentadecane = 15

hexadec

hexadecane = 16

alkanes

is based on the number of carbon atoms in the chain and always end with –ane

Alkyl groups

are substituents derived from alkanes

CH3CH2 CH2CH2–

butyl

CH3CH2CH2–

propyl

CH3CH2–

ethyl

CH3–

methyl

Alkyl Groups

are named according to their number of carbons, the same way the naming of alkane is done, but end with –yl instead of –ane.

Branched Alkyl groups

isopropyl, isobutyl, sec-butyl, tert-butyl, and neopentyl

isopropyl

isobutyl

sec-butyl

tert-butyl

neopentyl

Hyphens

to separate locants and the substituent name

cycloalkanes

are based according to the number of carbon atoms in the cyclic structure

an alkyl group will be obtained

If one hydrogen is removed from the end of the chain of an alkane

cyclopropane

3

cyclobutane

4

cyclopentane

5

cyclohexane

6

cycloheptane

7

cyclooctane

8

alkyl-substituted cycloalkane

If the number of carbons atoms in the ring is the same or greater than that of the alkyl group, the compound is named as an

cycloalkyl-substituted alkane

If the number of carbon in the largest alkyl group attached to the ring is greater than that of the ring, the compound is named as a