If you have a cycloalkane or cycloalkene with 2 substituents, so either way you number gives the same low numbers, how do you decide which gets the lowest number in the nomenclature? for example, what if a chlorine and methyl are 1 carbon apart?
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Assuming equal priority for all the substituents, you want the lowest number to be on the substituent that would come first alphabetically. Thus, a cyclohexane with a chlorine and methyl group one carbon apart would be 1-chloro-2-methylcyclohexane.
However, if there is a group with higher priority (say there was an alcohol on that same cyclohexane), that should ALWAYS be given the lowest possible number.
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