Give the IUPAC name of the following alkynes

SOLUTION:

Molecule 1.

1. Main chain: 6 carbons with triple bond (hexyne)
2. Numbering: lowest locant to the triple bond.
3. Substituents: methyl in position 6 ,
4. Name: 6-Methylhex-2-yne

Molecule 2.

1. Main chain: 5 carbons with triple bond (pentyne)
2. Numbering: lowest locant to the triple bond.
3. Substituents: cyclopentyl in position 4 .
4. Name: 4-Cyclopentylpent-1-yne

Molecule 3.

1. Main chain: 8-membered cycle (cyclooctyne)
2. Numbering: lower locant to the double bond and is numbered towards the triple.
3. Substituents: methyl in position 8 ,
4. Name: 8-Methylcycloocten-3-yne

Molecule 4.

1. Main chain: the longest that contains the triple bond (nonyne)
2. Numbering: lowest locant to the triple bond.
3. Substituents: 3-butyl,
4. Name: 3-Butylnon-1-yne