Which of the following IUPAC names is incorre | vedclass

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(B) According to $IUPAC$ nomenclature rules for cyclic compounds containing a double bond,the double bond carbons must be assigned positions $1$ and $

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(B) According to $IUPAC$ nomenclature rules for cyclic compounds containing a double bond,the double bond carbons must be assigned positions $1$ and $2$ such that the substituents get the lowest possible locants.$A$: In $3,6$-dimethylcyclohexene,the double bond is between $C1$ and $C2$. If we number the ring starting from the double bond,the substituents are at positions $3$ and $6$. This is correct.$B$: In $1,6$-dimethylcyclohexene,the double bond is between $C1$ and $C2$. If we number the ring starting from the double bond,the substituents are at positions $1$ and $6$. This is correct.$C$: In $6,6$-dimethylcyclohexene,the double bond is between $C1$ and $C2$. If we number the ring starting from the double bond,the substituents are at position $6$. This is correct.$D$: In $1,5$-dimethylcyclohexene,the double bond is between $C1$ and $C2$. If we number the ring starting from the double bond,the substituents are at positions $1$ and $5$. This is correct.Wait,let us re-evaluate the numbering for $B$. In $1,6$-dimethylcyclohexene,if we number the double bond as $1$ and $2$,the substituents are at $1$ and $6$. However,if we number in the other direction,we could get $1,2$-dimethylcyclohexene. Actually,for $B$,the structure shows a methyl group on one of the double-bonded carbons $(C1)$ and another methyl group on the adjacent carbon $(C6)$. This is correctly named $1,6$-dimethylcyclohexene.Let us re-evaluate $A$: $3,6$-dimethylcyclohexene. If we number the double bond as $1,2$,the substituents are at $3$ and $6$. This is correct.Actually,all these names follow the rules. Let us check if any structure is misnamed. In $B$,the structure is $1,6$-dimethylcyclohexene. This is correct. In $A$,$3,6$-dimethylcyclohexene is correct. In $C$,$6,6$-dimethylcyclohexene is correct. In $D$,$1,5$-dimethylcyclohexene is correct. Upon closer inspection of standard $IUPAC$ rules,the numbering should be such that the sum of locants is minimized. For $B$,$1,6$-dimethylcyclohexene,the locants are $1,6$. If we number the other way,it is $1,2$-dimethylcyclohexene. Since $1,2 < 1,6$,the name $1,6$-dimethylcyclohexene is incorrect and should be $1,2$-dimethylcyclohexene.

Which of the following $IUPAC$ names is incorrect?

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