IUPAC name format



IUPAC name format

Cyclic Compound:

S. prefix + P. prefix + word root + P. suffix + S. suffix

Acyclic Compound:

Prefix + word root + P. suffix + S. suffix

 Rules

1. Rules for selection of Carbon chain (parent chain)

Longest chain rule:  select longest continuous chain of carbon atom

Larger number of side chain:

If two c-chain have equal length (i.e having same number of c-atom), select c-chain which has greater number of side chains.

 Example:

Larger number of side chain rule

 

2.  Rules for numbering C-atom in parent chain

If only one side chain or substituent is present, the numbering of carbon atom is carried out in such a way that the carbon atom which carries substituent on side chain gets lowest possible number.

Larger number of side chain rule

If more than one side chain or substituent is present then the numbering of c-atom is carried in such a way that the sum of locant should be lowest. This rule is also known as lowest sum rule.

 

Note: Locant is the position or location number of side chain or substituent in parent chain.

Larger number of side chain rule

 

If two different substituents are present at equal position from two ends then the substituent which comes first in alphabetical order gets lowest position number.

Larger number of side chain rule