1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Bicyclic compounds nomenclature

  1. Mar 18, 2016 #1
    1. The problem statement, all variables and given/known data
    Name the following molecule by the IUPAC system of nomenclature.
    bicyclico.gif


    2. Relevant equations
    There are some rules.

    To name bicyclic alkanes, you follow these three steps:

    1- Count the total number of carbons in the entire molecule. This is the parent name (eg. ten carbons in the system would be decane)

    2-Count the number of carbons between the bridgeheads, then place in brackets in descending order. (eg. [2,2,1])

    3-Place the word bicyclo at the beginning of the name.

    3. The attempt at a solution

    I numbered the given structure as follows
    numbered.png

    And I considered the red line to be bridge
    redline.png


    redliness.png
    And I named it as Bicyclo [5,3]Decane
    But it is wrong . Answer is Bicyclo[3,3,1]nonane
     
  2. jcsd
  3. Mar 18, 2016 #2

    Borek

    User Avatar

    Staff: Mentor

    There is no carbon 6. To draw this molecules to scale you can't avoid an accidental crossing of the lines on the picture. Bonds go like 2-9 and 5-7 using your numbering scheme.
     
  4. Mar 18, 2016 #3

    DrClaude

    User Avatar

    Staff: Mentor

    You counted the atoms incorrectly. There is no atom where you wrote the number 6. The figure is not well drawn, so I can understand the confusion, but look at it as two cyclohexane molecules stuck together.
     
  5. Mar 18, 2016 #4
    I did not understand.
     
  6. Mar 18, 2016 #5

    Borek

    User Avatar

    Staff: Mentor

    There is no atom 6, there are no bonds 6-9, 6-7, 6-2 and 6-5. When you have something that is 3d, and you try to draw it on a flat surface of paper (which is always kind of projection), sometimes lines have to cross - but it doesn't mean they touch in the real molecule.
     
  7. Mar 18, 2016 #6
    Where are bridgeheads in this case?
     
  8. Mar 18, 2016 #7

    DrClaude

    User Avatar

    Staff: Mentor

    2 and 7.
     
  9. Mar 18, 2016 #8
    I am confused. How to identify bridge heads?
     
  10. Mar 18, 2016 #9

    DrClaude

    User Avatar

    Staff: Mentor

    They are the atoms that are part of the two rings.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Bicyclic compounds nomenclature
  1. IUPAC nomenclature (Replies: 4)

  2. Chemical Nomenclature (Replies: 5)

Loading...