Rule 1. Alkynes follow the formula CnH2n-2 and are named by replacing the -ane suffix of the alkane with the same number of carbons with -yne.
Rule 2. The principal chain chosen is the longest one containing the triple bond. The numbering should assign the lowest locators to the triple bond.
Rule 3. When the molecule has more than one triple bond, the principal chain is the one with the most triple bonds, and it is numbered from the end closest to one of the multiple bonds, ending the name in -diyne, -triyne, etc.
Rule 4. If the hydrocarbon contains both double and triple bonds, the following approach is used:
1. The principal chain is the one with the highest number of multiple bonds, regardless of whether they are double or triple.
2. It is numbered so that the multiple bonds collectively take the lowest locators. If there is a double bond and a triple bond at the same distance from the ends, the double bond takes precedence.
3. If the compound has a double bond and a triple bond, the name ends in -en-yne; if it has two double bonds and a triple, -dien-yne; with two triples and a double, the ending is -en-di-yne.
