Naming Organic Compounds (Cambridge (CIE) O Level Chemistry): Revision Note

Naming Organic Compounds

• The names of organic compounds have two parts: the prefix (or stem) and the end part (or suffix)

• The prefix tells you how many carbon atoms are present in the longest continuous chain in the compound

• The suffix tells you what functional group is on the compound

Structures of organic compounds

Further Rules for Naming Compounds

• When there is more than one carbon atom where a functional group can be located it is important to distinguish exactly which carbon the functional group is on

• Each carbon is numbered and these numbers are used to describe where the functional group is

• For example: 

  • Propan-1-ol is alcohol with an -OH functional group 

  • The 2 in the name indicates that the -OH group is located on the second carbon atom 

In propan-1-ol the -OH group is located on the first carbon atom

Alkanes

 Alkenes

Alcohols

Carboxylic acids

Naming Esters

• An ester is made from an alcohol and carboxylic acid

• The first part of the name indicates the length of the carbon chain in the alcohol, and it ends with the letters ‘- yl’

• The second part of the name indicates the length of the carbon chain in the carboxylic acid, and it ends with the letters ‘- oate’

• e.g. the ester formed from pentanol and butanoic acid is called pentyl butanoate

Diagram showing the origin of each carbon chain in ester

• Some examples of common esters:

Table showing the Formation of Esters