Name the following organic molecule (IUPAC)

Click For Summary

Discussion Overview

The discussion revolves around naming an organic molecule using IUPAC nomenclature. Participants analyze the structure of the molecule and propose various names based on their interpretations of the longest carbon chain and the position of double bonds.

Discussion Character

  • Homework-related, Debate/contested, Exploratory

Main Points Raised

  • One participant suggests the name 3-pentene, reasoning that the longest carbon chain is five carbons long.
  • Another participant corrects this by stating that 3-pentene would actually refer to a double bond between the 3rd and 4th carbon atoms, proposing that it should be named 2-pentene instead.
  • A later reply questions whether the name should be 2-ethyl-1-butene, considering the priority of the double bond in naming conventions.
  • One participant expresses uncertainty about the naming conventions, suggesting that the presence of a double bond might take precedence over the longest carbon chain.
  • Another participant proposes the name 3-methylidenepentane as an alternative IUPAC name.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the correct IUPAC name for the molecule, with multiple competing views and interpretations of the naming rules presented throughout the discussion.

Contextual Notes

There are unresolved assumptions regarding the interpretation of the molecular structure and the application of IUPAC naming rules, particularly concerning the prioritization of double bonds versus chain length.

PAR
Messages
30
Reaction score
0
Last edited by a moderator:
Physics news on Phys.org
3-pentene would actually be 2-pentene, and it would look something like this (excluding H's)

C-C=C-C-C or C-C-C=C-C

I see what you were trying to get at, but when you say 3-pentene, you're saying there is a 5 carbon chain that is the longest (correct) AND that there is a double bond connecting the 3rd and 4th carbon atoms =)

Here's my hint: try starting off at the double bond, and work your way up. What do you get now?
 
Last edited:
Slats18 said:
3-pentene would actually be 2-pentene, and it would look something like this (excluding H's)

C-C=C-C-C or C-C-C=C-C

I see what you were trying to get at, but when you say 3-pentene, you're saying there is a 5 carbon chain that is the longest (correct) AND that there is a double bond connecting the 3rd and 4th carbon atoms =)

Makes sense, so is it 2-ethyl-1-butene? Does the fact that it contains a double bond take priority over the longest carbon chain?
 
That's what I believe it to be =) Been over a year since I've done this, but I think it does for convience, as its just a C=C double bond. Different when it's a C=O double bond, as you could call it 3-pentanone. Either way, I think it's just easier to call it 2-ethyl-1-butene =)
 
IUPAC name is 3-methylidenepentane.
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
15K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 6 ·
Replies
6
Views
3K
Replies
19
Views
4K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
1
Views
3K