The IUPAC nomenclature of the compound above is

 CH3-CH=CH-CH-CH3

                          |

                         CH3

The IUPAC nomenclature of the compound above is 

A. 2-methylpent-4-ene

B. 4-methylpent-3-ene

C. 2-methylpent-3-ene

D. 4-methylpent-2-ene

The correct option is

D. 4-methylpent-2-ene

Explanation: 

The structure provided is 

• 

  ${\text{CH}}_3-\text{CH}=\text{CH}-\text{CH}\left({\text{CH}}_3\right)-{\text{CH}}_3$
  .
• Identify the longest carbon chain containing the double bond: The longest chain with the double bond has 5 carbons, making the parent alkane name "pentene".
• Number the carbon chain: The chain must be numbered from the end that gives the double bond the lowest possible number. Numbering from left to right, the double bond starts at carbon 2. Numbering from right to left, the double bond starts at carbon 3. Therefore, number from left to right. The double bond is between carbons 2 and 3, so the base name is pent-2-ene.
• Identify and number substituents: There is a methyl (
  

  ${\text{CH}}_3$
  ) group on the fourth carbon atom (when numbering from left to right).
• Combine everything: The correct IUPAC name is 4-methylpent-2-ene. 
• PQN: 27