What is the IUPAC name of this organic compound?

  • Thread starter Thread starter NoahCygnus
  • Start date Start date
  • Tags Tags
    Iupac Organic
Click For Summary

Discussion Overview

The discussion revolves around the IUPAC naming of a specific organic compound, focusing on the correct nomenclature for a compound containing cyclopentadiene and an alcohol functional group. Participants explore various naming conventions and interpretations based on IUPAC rules.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Mathematical reasoning

Main Points Raised

  • Some participants propose names such as 1-(cyclopent - 1', 4'-dienyl) methyl ethan-1-ol and 1-methyl - 1 - (cyclopent-1',4'-dienyl) ethan-1-ol, noting that the textbook does not provide an answer.
  • Another participant suggests naming it 2-(2-hydroxyprop-2-yl)cyclopentadiene but questions its correctness as it does not indicate the alcohol functional group.
  • There is a discussion about the numbering of the ring atoms, with some arguing that it should prioritize the double bonds, leading to the designation of cyclopenta-1,3-dienyl.
  • One participant expresses confusion regarding the numbering of the ring and insists that the carbon attached to the main chain should be considered as 1'.
  • Another participant mentions that ChemSketch identifies the compound as 2-(cyclopenta-1,4-dien-1-yl)propan-2-ol.
  • Some participants emphasize the importance of alphabetical order in naming substituents, suggesting that the correct names should reflect this rule.

Areas of Agreement / Disagreement

Participants express multiple competing views on the correct IUPAC name for the compound, with no consensus reached on a single naming convention. Disagreements arise regarding the numbering of the ring and the prioritization of substituents.

Contextual Notes

There are limitations regarding the assumptions made about the structure and functional groups, as well as the interpretations of IUPAC rules. Some participants highlight the need for clarity on the position of substitution on the ring.

NoahCygnus
Messages
96
Reaction score
2
244518

Well I have two possible answers, it's either 1-(cyclopent - 1', 4'- dienyl) methyl ethan-1-ol or 1-methyl - 1 - (cyclopent-1',4'-dienyl) ethan-1-ol.
Unfortunately the answer wasn't provided in the textbook.
 
Chemistry news on Phys.org
What is 1-methylethanol?
I would find it simplest to name it 2-(2-hydroxyprop-2-yl)cyclopentadiene, but that doesn't name it as an alcohol so I suspect is not correct.
Alternatively, 2-(2-cyclopentadienyl)-2-propanol?
Note that (i) you must specify the position of substitution on the ring; (ii) the ring is 1,3-cyclpoentadiene, not 1,4. Actually you can just say cyclopentadiene, because there is only one possible cyclopentadiene.
 
mjc123 said:
What is 1-methylethanol?
I would find it simplest to name it 2-(2-hydroxyprop-2-yl)cyclopentadiene, but that doesn't name it as an alcohol so I suspect is not correct.
Alternatively, 2-(2-cyclopentadienyl)-2-propanol?
Note that (i) you must specify the position of substitution on the ring; (ii) the ring is 1,3-cyclpoentadiene, not 1,4. Actually you can just say cyclopentadiene, because there is only one possible cyclopentadiene.
244529

Nomenclature rules state that the functional group has a higher priority than a ring or double bonds, so the main chain will be the one marked by blue. I screwed up in the first try, I didn't see that there was a propane chain. I redid the problem and came with the answer 2-(cyclopent-1',4'-dienyl) propan-2-ol.
 
The numbering of the ring atoms is such as gives the lowest numbers to the double bonds (not such as puts the substituent on atom 1). Thus it is cyclopenta-1,3-dienyl and the substituent is on atom 2.
 
mjc123 said:
The numbering of the ring atoms is such as gives the lowest numbers to the double bonds (not such as puts the substituent on atom 1). Thus it is cyclopenta-1,3-dienyl and the substituent is on atom 2.
cyclopenta-1,3-dineyl? 1,3? I don't get how you numbered the ring, you have to number the carbon of the ring attached to the main chain as 1'. See diagram. There is no double bond on 3' carbon of the ring.
 
Maybe I'm thinking of cyclopentadiene as the base compound. To me, that's a cyclopentadiene with a substituent on atom 2. If IUPAC thinks differently, they're wrong, that's all I can say.
 
ChemSketch calls it 2-(cyclopenta-1,4-dien-1-yl)propan-2-ol.
 
I think it's 1-(cyclopent-1,4-dienyl) 1-methyl-ethanol.
Cyclo is starting with "C" and methyl is starting with "M" When there are two substituents, you write them alphabetically
 
NoahCygnus said:
View attachment 244518
Well I have two possible answers, it's either 1-(cyclopent - 1', 4'- dienyl) methyl ethan-1-ol or 1-methyl - 1 - (cyclopent-1',4'-dienyl) ethan-1-ol.
Unfortunately the answer wasn't provided in the textbook.
IUPAC RULE IS TO WRITE SUBSTITUENTS ALPHABETICALLY THEREFORE IT WOULD HAVE BEEN THE FIRST ONE BUT YOU MADE SLIGHT MISTAKE THE CORRECT NAMES ARE:-
2-(cyclo penta-1', 4'- dienyl) propan-2-ol [most detailed]
or 2-(cyclo penta-1, 4- dienyl) propan-2-ol [without ']
or 2-(1,4-cyclo pentadienyl)-2-propanol [simplest]
 
  • #10
NoahCygnus said:
View attachment 244518
Well I have two possible answers, it's either 1-(cyclopent - 1', 4'- dienyl) methyl ethan-1-ol or 1-methyl - 1 - (cyclopent-1',4'-dienyl) ethan-1-ol.
Unfortunately the answer wasn't provided in the textbook.
You have to start numbering from the foremost carbon attached to the functional group (which automatically becomes the main chain), number the first carbon of the cyclo group as 1 and know that it isn't included in the main chain as it is a 'substituent'
So the answer is 1-(Cyclopent-1,4 dienyl) 1-Methyl Ethan-1-ol. Feel free to ask any questions!
 

Similar threads

Replies
1
Views
4K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 5 ·
Replies
5
Views
4K
  • · Replies 2 ·
Replies
2
Views
3K
Replies
19
Views
4K
Replies
1
Views
4K
  • · Replies 8 ·
Replies
8
Views
5K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 6 ·
Replies
6
Views
5K