The correct structure of 2,6-Dimethyl-dec-4-ene is :

To determine the correct structure of 2,6-Dimethyl-dec-4-ene, let us break down its IUPAC name step-by-step:

1. Identify the parent carbon chain: The word root "dec" indicates that the longest continuous carbon chain containing the double bond consists of 10 carbon atoms.
2. Identify the principal functional group: The suffix "4-ene" indicates the presence of a carbon-carbon double bond (C=C) starting at carbon-4 (i.e., between carbon-4 and carbon-5).
3. Identify the substituents: The prefix "2,6-dimethyl" indicates that there are two methyl groups (-CH₃) attached to the main chain at carbon-2 and carbon-6.

Now, let us analyze the structure in Option 1 by numbering the longest chain starting from the top-right terminal carbon:

C1: CH₃ (terminal methyl on the right)
C2: CH (bearing a methyl substituent)
C3: CH₂
C4: CH (first carbon of the double bond)
C5: CH (second carbon of the double bond)
C6: CH (bearing a methyl substituent)
C7: CH₂
C8: CH₂
C9: CH₂
C10: CH₃ (terminal methyl at the bottom right)

This numbering gives a 10-carbon parent chain with a double bond at position 4 and methyl groups at positions 2 and 6. Therefore, the structure in Option 1 represents 2,6-Dimethyl-dec-4-ene.