Name the following alkynes taking the cycle as the main chain.

alkyne nomenclature

SOLUTION:

Molecule 1.

molecule 01

1. Main chain: 5-membered cycle (cyclopentane)

2. Numbering: start at the carbon of the ethynyl group (alphabetically first)

3. Substituents: 1-ethynyl and 2-methyl.

4. Name: 1-ethynyl-2-methylcyclopentane

 

Molecule 2.

molecule 02

1. Main chain: 6-membered cycle (cyclohexane)

2. Numbering: assigning the minor locants to the substituents ( 1,2,4 )

3. Substituents: 1-chloro, 2-2-propynyl , and 4-methyl.

4. Name: 1-Chloro-4-methyl-2-(2-propynyl)cyclohexane

 

Molecule 3.

molecule 03

1. Main chain: 6-membered cycle (cyclohexane)

2. Numbering: assigning the minor locants to the substituents ( 1,2,4 )

3. Substituents: 1-(2-butynyl) , 2-ethyl, and 4-methyl.

4. Name: 1-(2-butynyl)-2-ethyl-4-methylcyclohexane