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Alkane Common and Systematic Naming (Part 3 of Alkane Naming)

I... am sorry for not posting anything in a while. I get lazy when I have to type something in code or just something long. Just in advance, I haven't done the nomenclature for cycloalkanes yet. I will do that... soon, after this.

Let's say I have Butyl cyclo hexane. Let us break it down. Butyl cyclohexane, \(\Rightarrow\) Six carbon chain. Oh, but we have cyclo \(\Rightarrow\) A ring of carbon chain.

And we have the butyl, hence a four carbon chain branches off.

which is...

Butylcyclohexane

Butylcyclohexane

Now wait a moment. I could've done this just as easily.

Butylcyclohexane2

Butylcyclohexane2

They're both fundamentally two different structures! We have two ways of differentiating (not calculus differentiation :P) these two molecules.

  • Common Naming.

If I simply say butyl cyclo hexane \(\Rightarrow\) then it's this one.

Butylcyclohexane

Butylcyclohexane

The second one I drew would definitely be a cyclo hexane however, then ring is bonded to a carbon which is bonded to two other carbons \(\Rightarrow\) sec butylcyclo hexane or sometimes in textbooks they write it as s-butyl cyclo hexane.

And the sec means the ring or whatever is attached to a carbon which is attached to two other carbons.

Now think of a situation like this.

Butylthing3

Butylthing3

I guess I could say that the ring is attached to a carbon and it branches off later separately.

We call this an iso butylcyclo hexane. Think of it like the main chain is attached to a carbon which is away from the branching off part. (Hope that helped... somehow).

And then the last one,

Butyltert

Butyltert

We have a situation where the ring is bonded to a carbon which is bonded to three other carbons. Hence, it is called tert butylcyclo hexane or t-butylcyclo hexane.

  • Systematic Naming.

Let's look at the sec butyl cyclo hexane and see how it will be named systematically.

So first of all, the group that comes off the cyclo hexane.

Secbut

Secbut

It is a three carbon group with a methyl group attached.

In other words, 1 methyl propyl. 1 - for being attached to the first carbon of the propyl group. Methyl because it is just one carbon.

That... is just the name of that group that branches off the main carbon ring. And we put the branching group's name in brackets (I think...).

Hence it becomes, (1-methyl propyl) cyclo hexane.

Now this one...

2-methylthing

2-methylthing

Now, the methyl group branches off the second carbon \(\Rightarrow\) 2-methyl and the whole group is a propyl/three carbon group \(\Rightarrow\) 2-methyl propyl.

That's just the side group, we need to name the whole molecule!

And of course, it's still cyclo hexane \(\Rightarrow\) (2-methyl propyl) cyclo hexane.

Lastly,

terty

terty

.

Ahaha, this is interesting. So we have two methyl groups attached to an ethyl group. And both of those methyl groups are bonded to the first carbon of the ethyl group.

So we write, di methylethyl. But we gotta show which carbon those methyl groups are bonded to \(\Rightarrow\) 1,1 - di methyl ethyl.

Of course that's not the end of it, we have to name the whole molecule!~

Thus, it becomes... (1,1 - di methyl ethyl) cyclo hexane.

I haven't done a note on how to name carbon rings yet... I think you guys get the idea. But I'll write another note or so if you found this confusing.

Feel free to comment on any questions, queries etc. I am writing this post at 2:33 am... So it's likely that I might have made a few mistakes. If so, feel free to correct me.

^^ That is all.

Note by Vishnuram Leonardodavinci
3 years ago

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Nice post, brother. I am highly interesred in nomenclature and this post was awesome. I have a question. When is sec- used?? Himadri Shee · 3 years ago

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@Himadri Shee Ah, sec is used when you have the second carbon of a smaller chain bonded to some other major chain, group, ring or something. It is generally used because it's a common name (like ammonia or ammonium) and because the systematic naming is a bit more complex. However, the systematic naming is, in my opinion more intuitive. ^^ Vishnuram Leonardodavinci · 3 years ago

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@Vishnuram Leonardodavinci Well, even IUPAC accepts these common names. So, I prefer them more as they are easier to use. Priyansh Sangule · 3 years ago

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@Priyansh Sangule But I prefer systematic names because they go by the rules and I don't have to jam in the common names. Himadri Shee · 3 years ago

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@Himadri Shee I prefer using the one which is easier . Priyansh Sangule · 3 years ago

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@Vishnuram Leonardodavinci Thanks. I have a doubt. Which chain is chosen as the main chain when cyclic ring and aliphatic chain are joined? For example, which would be correct: Cyclopropylpropane or Propylcyclopropane? Himadri Shee · 3 years ago

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@Himadri Shee Cyclo will go in first. So it must be Cyclo propyl propane . Priyansh Sangule · 3 years ago

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This is phenomenal! I just started learning about OC and this is really interesting. Finn Hulse · 3 years ago

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@Finn Hulse ^^ That's good to see. Vishnuram Leonardodavinci · 3 years ago

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@Vishnuram Leonardodavinci :D Finn Hulse · 3 years ago

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Nice post! Some little things I'll like to suggest~

Name the compounds with spacing. This will help the reader to understand the naming better.

For example~ tertbutylcyclohexane seems a bit complex as compared to tert-butyl cyclohexane

That's how my teachers teach me. Simple and logical approach.

Thank You for this nice post!

It helped me review the topic :D

Keep Up the good work , man ! Priyansh Sangule · 3 years ago

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@Priyansh Sangule Alright! I shall edit it. Thanks for the feedback. ^^ Vishnuram Leonardodavinci · 3 years ago

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@Vishnuram Leonardodavinci No no no! Not that way. Make It Like : s-butyl cyclohexane

I meant spacing and not " - " .

Thanx for considering my feedback. Priyansh Sangule · 3 years ago

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@Priyansh Sangule Owhh, ahah, alright. ^^ Vishnuram Leonardodavinci · 3 years ago

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@Vishnuram Leonardodavinci Yeah! Like That! :D Priyansh Sangule · 3 years ago

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@Priyansh Sangule Consider it done. ^_^ Vishnuram Leonardodavinci · 3 years ago

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Extremely helpful Subham bhuyan Bhuyan · 1 year, 5 months ago

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Nice post!!Extremely informative...loved it!! Tanya Gupta · 3 years ago

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