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Nomenclature of Compounds Containing One Functional Group

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The following additional rules are applied while naming organic compounds containing one functional group.

1) Parent chain : The parent chain must contain the functional group even when it does not denote the longest chain.

Take a look at the way numbering is done in the following compounds :

In IUPAC Nomenclature of 3-Ethylpent-1-ene, double bond is given preference
IUPAC nomenclature of compounds containing functional groups : functional group is given preference

2) Numbering of the parent chain should always be done from that end which is nearer to the functional group.

IUPAC nomenclature of compounds containing functional groups : functional group is given preference while numbering

3) When a carbon containing functional group such as -CHO, -COOH, -COCl is present at the terminal, the carbon of the functional group is always assigned number 1.

Carbon containing functional group is assigned number 1 : 2-Ethylbutan-1-oic acid

Compare the way numbering is done :

IUPAC nomenclature of compounds containing functional groups :
IUPAC nomenclature of compounds containing functional groups :

Name of the compound

The suffix of the functional group is added to the end of the word root with its positional number.

Compare :

Without any functional group

IUPAC nomenclature without functional groups : 2-Methylbutane

With a functional group

IUPAC nomenclature with functional groups : 2-Methylbutane

Note : Since 'ol' begins with a vowel, the terminal 'e' from primary suffix is dropped (already discussed in nomenclature introduction ).

What is the name of the following compound :

Question

More than one occurrence of the same functional group

When the same functional group appears more than once in the chain, suitable prefixes such as di (for two), tri (for three), tetra (for four) etc., are added along with their positional numbers.

More than one occurrence of a functional group : Propane-1,2,3-triol

Notice that 'e' from primary suffix 'ane' is retained because 't' is a consonant.

When the location of a functional group is 1 and there is no ambiguity, the '-1-' from the name can be omitted.

2-Ethylbutan-1-oic acid   =   2-Ethylbutanoic acid

Ethane-1,2-diol ( '1' cannot be omitted from '-1,2-')

true/false

The following compound is named correctly :

True or false
More examples on compounds containing one functional group
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