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Name the following organic molecule (IUPAC)

  1. Mar 4, 2011 #1


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    Last edited by a moderator: May 5, 2017
  2. jcsd
  3. Mar 4, 2011 #2
    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: Mar 4, 2011
  4. Mar 4, 2011 #3


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    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?
  5. Mar 4, 2011 #4
    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 =)
  6. Mar 5, 2011 #5


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    Staff: Mentor

    IUPAC name is 3-methylidenepentane.
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