[Chemistry Form 5] IUPAC Rules

1. Identify the longest continuous carbon chain, also called the parent chain (which includes the functional group, if there is any). Then name it.
   
   
2. Identify and name groups (or substituents) attached to the parent chain.
   
   
3. Number the chain consecutively, starting at the end that is nearest to a substituent group.
   
   
4. Designate the location of each substituent group by an appropriate number and name.
   
   
5. Use prefixes like di, tri and tetra to indicate the number of times the substituent groups occur.
   
   
6. In alkene, the root/parent chain must be numbered from the end that is nearest to a double bond carbon atom. If the double bond is in the centre of the chain, the nearest substituent rule is used to determine the end where numbering starts.

** IUPAC - International Union of Pure and Applied Chemistry

Did you know?

Pears are ethylene producers. So, instead of storing them next to ethylene-sensitive vegetables like carrots, place the next to other ethylene producers in the coldest part of the refrigerator. Ethylene or ethene, whose formula is C₂H₄, is the simplest alkene.