Naming Organic Compounds (Cambridge O Level Chemistry)

• 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

• 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