# Why is 5-chloro-1-methylcyclopentene not named 3-chloro-2-methylcyclopentene? [duplicate]

Why is the ring numbered the way it is? What is it about the double bond that makes it so?

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Acoording to the IUPAC rules for nomenclature of the halo compounds the $$\ce{Cl}$$ here is treated like $$\ce{CH3}$$. And also according to rule, the double bond have preference over the groups other than functional groups.