Nomenclature, cyclohexene priority

[babowc]

This alkene is 1-methyl-6-nitrocyclohexene,

but why can't it be 2/3 instead? I thought lowest # total is preferred?

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[Slumber]

This alkene is 1-methyl-6-nitrocyclohexene,

but why can't it be 2/3 instead? I thought lowest # total is preferred?

Always number the chain that gets you closest to the first sub. 1 C - methyl > 2 C methyl.

what you said is true, but only if you have multiple ways to number the chain (aka, same length and same distance to the first sub.)

 

[gn4]

i'm interested to know as well. I thought it could be 2/3

 

[gn4]

Always number the chain that gets you closest to the first sub. 1 C - methyl > 2 C methyl.

what you said is true, but only if you have multiple ways to number the chain (aka, same length and same distance to the first sub.)

thanks for explanation

 

[babowc]

This always confused me...
so we're numbering 1-6 in CC direction.

what do you mean by "what you said is true, but only if you have multiple ways to number the chain (aka, same length and same distance to the first sub."

Thanks alot, you're a great help!

 

[Slumber]

This always confused me...
so we're numbering 1-6 in CC direction.

what do you mean by "what you said is true, but only if you have multiple ways to number the chain (aka, same length and same distance to the first sub."

Thanks alot, you're a great help!

First thing first, find the longest chain, then apply what I said from the previous post, number the chain in such a way that will get you closest to the first sub.

After applying the first 2 rule, if you still have multiple ways to number that chain (aka if they're equal distance to their first sub), THAT's when you try to get the lowest numbers to the subs.

 

[roquer2]

So I worked this problem out without thinking about it too much.

This is how I concluded:

-Named it as cyclohexene

-Started with the carbon that is substituted first (the vinylic methyl)

-#ed around until I included the nitro group

I got: 1-methyl-6-nitrocyclohexene

I can see the confusion. And I agree, lowest priority wins. However, in this case you have the first carbon of the chain with a substituent, and from my understanding that gets the first priority. Hope this helps

 

[Dotoday]

You start numbering from the double bond. Double bond gets the priority. Since a methyl group is atrached to a carbon with a double bond ( vinylic carbon), you start numbering from this carbon, then the second carbon is the one that is double bonded to the first carbon. You go on from there. Hope this helps. Good luck.

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