IUPAC system and IUPAC rules of Naming Alcohols

In the common system, alcohols are named as alkyl alcohols. The word alcohol is added after the name of the alkyl group to which the hydroxyl group is attached. For e.g., CH3OH is methyl alcohol.

In the IUPAC system, the names of saturated alcohols are derived from corresponding alkenes by replacing 'e' of alkenes by 'ol'

Some examples are shown below.

The numbering is done such that the carbon atom attached to the

-OH group gets the lowest number.

For naming polyhydric alcohols, the name of the alkane is retained and the ending -e is not dropped. Thus dihydric alcohols are named as alkane diols and trihydric alcohols are named as alkene triols.

The position of carbon atoms carrying -OH groups are indicated by locants written after the name of alkene. The number of hydroxyl groups is indicated by adding the multiplicative prefix di, tri, tetra etc., before the suffix-ol.

IUPAC nomenclature of cyanide or nitrile

In the IUPAC system, suffix nitrile is added to the name of the hydrocarbon atoms i.e. they are named as Alkanenitriles. The carbon atom of the -CN group is also counted in the parent chain. For determining the position of the substituent in a chain, the nitrile carbon is numbered as 1.

Example:

IUPAC system and IUPAC rules of naming Aldehydes &  Ketones

The IUPAC names of open chain aliphatic aldehydes and ketones are derived from the names of the corresponding alkanes by replacing the ending -e with -al and -one respectively.

The following steps are followed:

a) The longest carbon chain containing the carbonyl carbon is taken to decide the name of the parent alkane.

b) The carbon chain is numbered from the end nearer to the carbonyl group and the substituents are prefixed in alphabetical order along with Arabic numerals including their positions in the carbon chain. The carbon of the aldehydic group and the carbonyl carbon in cyclic ketones always get the number 1.

c) When the aldehyde group is attached to a ring, the numbering of the ring carbon atoms starts from the carbon atom attached to the aldehyde group. The suffix carbaldehyde is added after the full name of the hydrocarbon.

The simplest aromatic aldehyde carrying the aldehyde group on a benzene ring is benzaldehyde.

Other ring substituted aromatic aldehydes are derivatives of benzaldehyde is ortho-hydroxy benzaldehyde.

IUPAC system and IUPAC rules of naming carboxylic acid

The common names end with the suffix-ic acid .In the IUPAC system, the monocarboxylic acids are named as alkanoic acids. The name of the acid is derived by replacing the terminal 'e-' of the corresponding alkane with '-oic acid'. Carboxyl carbon is always given number one while numbering the carbon atoms of the parent chain.

Examples:

IUPAC system and IUPAC rules of naming of acid derivative of carboxylic acid

In the following examples the IUPAC names are color coded, and common names are given in parentheses.

• Esters: The alkyl group is named first, followed by a derived name for the acyl group, the oic or ic suffix in the acid name is replaced by ate.

e.g. CH₃(CH₂)₂CO₂C₂H₅ is ethyl butanoate (or ethyl butyrate).

Cyclic esters are called lactones.

• Acid Halides: The acyl group is named first, followed by the halogen name as a separate word.

e.g. CH₃CH₂COCl is propanoyl chloride (or propionyl chloride).

• Anhydrides: The name of the related acid(s) is used first, followed by the separate word "anhydride".

e.g. (CH₃(CH₂)₂CO)₂O is butanoic anhydride & CH₃COOCOCH₂CH₃ is ethanoic propanoic anhydride (or acetic propionic anhydride).

• Amides: The name of the related acid is used first and the oic acid or ic acid suffix is replaced by amide (only for 1º-amides).

e.g. CH₃CONH₂ is ethanamide (or acetamide).

2º & 3º-amides have alkyl substituents on the nitrogen atom. These are designated by "N-alkyl" term(s) at the beginning of the name.

e.g. CH₃(CH₂)₂CONHC₂H₅ is N-ethylbutanamide; & HCON(CH₃)₂ is N,N-dimethylmethanamide (or N,N-dimethylformamide).

Cyclic amides are called lactams. A Greek letter identifies the location of the nitrogen on the alkyl chain relative to the carboxyl carbonyl group.

• Nitriles: Simple acyclic nitriles are named by adding nitrile as a suffix to the name of the corresponding alkane (same number of carbon atoms).

Chain numbering begins with the nitrile carbon . Commonly, the oic acid or ic acid ending of the corresponding carboxylic acid is replaced by onitrile.

A nitrile substituent, e.g. on a ring, is named carbonitrile.