Nomenclature
Alkynes are named like the corresponding alkanes, replacing the ending -ane with -yne and indicating the position of the triple bond with a locant.
- Look for the longest chain bearing the triple bond.
- The chain is numbered assigning to the triple bond the lowest possible numerals, exception made when there is a dominant function.
- If there are substituents they must be preceded by the corresponding numerals.
- In the case there are two possible equivalent numberings, that with the lowest substituent numerals will be taken.
- Chains bearing a triple bond that must act as a substituent are named "alkynyl".
- When one finds an open chain with triple and double C=C bonds (alkenynes), the numbering will start by the nearest end to one of them.
- If the double C=C and triple bonds are equidistant to both ends of the chain, the double bond takes the priority.
- Should there be other substituents of higher priority, the numbering will start by them.
Here are some key examples:
