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Topic: Understanding the IUPAC name for Borneol:  (Read 2479 times)

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Offline bubblegumpi

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Understanding the IUPAC name for Borneol:
« on: December 07, 2019, 08:35:14 AM »
endo-1,7,7-Trimethyl- bicyclo[2.2.1]heptan-2-ol

So I have some college chem but never took organic chem but consider myself an organic enthusiast and its my favorite type of chemistry.

What does the :
endo mean?
What are the carbons in []'s [2.2.1] and why use "." instead of ","
The bicyclo refers to the fact its a 3d ring shape (Would make Y when looking top down)?
Which C atoms make up the heptan group?

Thanks
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Offline billnotgatez

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Re: Understanding the IUPAC name for Borneol:
« Reply #1 on: December 07, 2019, 09:33:25 AM »
https://iupac.org
And many other sites when you GOOGLE
Quote
iupac

WIKI also has some information
https://en.wikipedia.org/wiki/Borneol
« Last Edit: December 07, 2019, 09:48:57 AM by billnotgatez »

Offline hollytara

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Re: Understanding the IUPAC name for Borneol:
« Reply #2 on: December 07, 2019, 11:38:30 AM »
Any bicyclic compound has two bridgeheads (shared by both rings) and three bridges. 

The bicycloalkane is named by the total number of atoms in the two ring system - here 7 carbons, so "bicycloheptane".

The lengths of the three bridges are indicated using the brackets - here two 2 carbon bridges and one 1 carbon bridge so [2.2.1]  The choice of a period over a comma was relatively arbitrary - but note that numbers separated by commas usually indicate locations of substituents.

The "endo" tells you that the OH is on the opposite side (trans) from the smaller (1 carbon) bridge.  If you make a model, you will see that this is the more "interior" looking position compared to the position cis to the 1 carbon bridge, which is called "exo". 

Numbering usually starts at a bridgehead then goes around the biggest bridge then the second then the smallest. 

Well, you asked!

If you want a quick review of basic organic topics check out the book by Jakob Fredlos.

Offline bubblegumpi

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Re: Understanding the IUPAC name for Borneol:
« Reply #3 on: December 08, 2019, 02:34:03 PM »
https://iupac.org
And many other sites when you GOOGLE
Quote
iupac

WIKI also has some information
https://en.wikipedia.org/wiki/Borneol

I went to google that's how I got here. Also you would have to be a genius to learn all the IUPAC rules from their site and not having any questions.

Any bicyclic compound has two bridgeheads (shared by both rings) and three bridges. 

The bicycloalkane is named by the total number of atoms in the two ring system - here 7 carbons, so "bicycloheptane".

The lengths of the three bridges are indicated using the brackets - here two 2 carbon bridges and one 1 carbon bridge so [2.2.1]  The choice of a period over a comma was relatively arbitrary - but note that numbers separated by commas usually indicate locations of substituents.

The "endo" tells you that the OH is on the opposite side (trans) from the smaller (1 carbon) bridge.  If you make a model, you will see that this is the more "interior" looking position compared to the position cis to the 1 carbon bridge, which is called "exo". 

Numbering usually starts at a bridgehead then goes around the biggest bridge then the second then the smallest. 

Well, you asked!

If you want a quick review of basic organic topics check out the book by Jakob Fredlos.


Thank you that makes total sense, thats what I love about naming in organic chem it totally describes even if its a bit long, what the molecule is. I think its fun to try and name them when I see them, or guess properties based off shapes.

So what if the 6 carbon ring (bottom one) had a double bond in it it wouldn't be cyclo but rather bezyl? Or does the fact that its technically 7 carbon ring invalidate the use of the benzyl, or would it need three double bonds to be considered benzyl? 
« Last Edit: December 08, 2019, 02:46:52 PM by bubblegumpi »
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Offline Enthalpy

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Re: Understanding the IUPAC name for Borneol:
« Reply #4 on: December 08, 2019, 07:10:17 PM »
Can you have a bridge on a C6 aromatic ring? The bond are in the wrong direction. And not with the pending methyl, as this would require pentavalent carbon.
Even double bonds normally don't happen at bridgehead carbon (Bredt's rule), and here not with the pending methyl. That would allow only 2 double bonds here, resembling norbornadiene.

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