Question

Name the compound
(CH3)2CHCCCH3
1. 2-methyl-3-pentyne
2. 3-methyl-1-pentyne
3. 5-methyl-2-pentyne
4. 4-methyl-2-pentyne
5. 3-methyl-2-hexane
6. 4-methyl-2-pentene

Can you also explain how to draw their structure?

Answer 1

The compound is 4-methyl-2-pentyne.

To draw the structure, first draw the five-carbon chain and label each carbon as 1 through 5.

CH3–C–C–C–C–CH3
1 2 3 4 5

Next, identify the location of the triple bond, which is between carbons 2 and 3.

CH3–C≡C–C–C–CH3
1 2 3 4 5

Finally, add the methyl group (CH3) to carbon 4.

CH3–C≡C–C(CH3)–C–CH3
1 2 3 4 5

This is 4-methyl-2-pentyne.