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Not understanding Fischer projections

  1. Dec 3, 2015 #1
    This is whats confusing me.
    Wikipedia says that "All bonds are depicted as horizontal or vertical lines."
    Then it shows a picture of D glucose chain with diagonal bonds. (the double bond and the hydrogen).
    Why is it drawn with diagonal bonds if its supposed to be only vert or horiz bonds?
    thanks for any help
     
  2. jcsd
  3. Dec 3, 2015 #2
    Hi ppppparker:

    It would help if you post a link to the Wikipedia article, and you include the exact text from the article you want to ask about.

    Regards,
    Buzz
     
  4. Dec 3, 2015 #3

    TeethWhitener

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    Gold Member

    Because the Wikipedia article on Fischer projections is poorly written. It should say something to the effect of "All relevant bonds between chiral centers are depicted as horizontal or vertical lines." There are a few competing conventions for Fischer projections (Do you draw out the terminal aldehyde or just write it as CHO? Do you draw all bonds as horizontal or vertical, or just the ones to chiral centers?), but the important takeaway is that at the very least, the bonds between chiral centers are drawn as horizontal or vertical lines. This is the purpose of Fischer projections: to provide a shorthand for showing stereochemistry of molecules (like sugars) with a large number of chiral centers.

    EDIT: Here's the link in question.
     
  5. Dec 3, 2015 #4
    Hi TeethWhitener:

    I have to agree with you that the article is poorly written. Your explanation is much clearer. Perhaps you might enter a comment on the talk page and suggest how the article might be improved. I have found that this does not often help, but sometimes it does.

    Regards,
    Buzz
     
  6. Dec 3, 2015 #5
    "All relevant bonds between chiral centers are depicted as horizontal or vertical lines."

    that makes total sense to me now. I see why textbook was explaining on and on about chirality now. thanks.
    i thought that I must be missing something really dumb.
     
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