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Wedge-and-dash Molecular Structures in 2-dimensions

  1. Nov 19, 2009 #1
    1. The problem statement, all variables and given/known data
    I'm having trouble drawing a wedge-and-dash, 2 dimensional molecular structure for Vitamin C (ascorbic acid). All of the diagrams I've looked at (on the Wikipedia page, and some .edu websites) are incomplete: they either don't include the carbon and/or hydrogens molecules, or the wedges and dashes

    2. Relevant equations

    none.

    3. The attempt at a solution

    I've tried drawing it based on other diagrams found on the internet, but they are all incomplete (none of them actually inclde C6H8O6 (6 carbon, 8 hydrogen, and 6 oxygen). As I said earlier, the creators of the 2d diagrams often omit some of the carbons and hydrogens, or don't put in the wedges/dashes.

    I've also tried looking at 3d models to figure out when wedges and dashes should be put in, but its hard to tell whether or not the angle of the bond is coming towards you, away from you, or neither one.

    I've mostly been using this website to try and figure out how to do this.

    http://www.3dchem.com/molecules.asp?ID=69#
     
    Last edited: Nov 19, 2009
  2. jcsd
  3. Nov 19, 2009 #2

    chemisttree

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    The stereochemistry you are asking about usually is shown only for select carbons... the ones that exhibit stereochemistry. In ascorbic acid there are two stereocenters. One bears a hydroxyl and the other is attached to the lactone ring. The hydrogen at that carbon is dashed in the Wiki drawing. Since the hydrogen is dashed, the carbon of the side chain (not the cyclic structure) is assumed to be wedged. It is difficult to show the absolute stereochemistry about that carbon by wedging the 2 carbon side chain but it is wedged nonetheless.

    The stereochemistry about the adjacent carbon bearing the hydroxyl shows the OH group as being wedged. The hydrogen attached to the same carbon is not shown but is assumed to be dashed.
     
  4. Nov 19, 2009 #3
    Thanks for your help! I wasn't familiar with a lot of the terminology you used (sophomore in high school) but I think I mostly understood what you were saying. Here's what I came up with (let me know if I got it right/wrong):
    http://img691.imageshack.us/img691/7160/2ddrawing.png [Broken]
     
    Last edited by a moderator: May 4, 2017
  5. Nov 20, 2009 #4

    chemisttree

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    I can't decipher the stereochemistry around the carbon bearing the OH on the side chain. You have the hydrogen, hydroxyl and the lactone ring all wedged. This means that they are all coming up out of the plane of the drawing. This makes understanding the stereochemistry about that carbon impossible.
     
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