Nomenclature:IUPAC Find the longest chain containing the triple bond. Change -ane ending to -yne. Number the chain,starting at the end closest to the triple bond. Give branches or other substituents a number to locate their position. Chapter 9 3Chapter 9 3 Nomenclature: IUPAC • Find the longest chain containing the triple bond. • Change -ane ending to -yne. • Number the chain, starting at the end closest to the triple bond. • Give branches or other substituents a number to locate their position