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Practicing Structural Drawings

  1. Jun 28, 2009 #1
    Did I draw this correctly?
    http://img151.imageshack.us/img151/7946/correctj.jpg [Broken]

    Thank you
     
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Jun 29, 2009 #2

    chemisttree

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    Yep. Can you explain why you don't need to show the stereochemistry about the central carbon atom?
     
  4. Jun 29, 2009 #3
    Thanks, and no I cannot, since I'm not sure what that means. Care to to help me out?
     
  5. Jun 29, 2009 #4

    Wax

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    I probably shouldn't spoon feed you but Stereochemistry is just a complicated way of saying, all 4 sides are not equal. The middle carbon is connected to -OH and -OH, those two are identical. Therefore, they will be on the same plane and not possible to draw in 3D or Stereochemistry.

    All four sides equal then no Stereochemistry.
    All four sides different then draw Stereochemistry.
     
  6. Jun 29, 2009 #5
    Can you give me an example of a drawing where you need to show Stereochemistry and how you do it please?

    Thanks.
     
  7. Jun 29, 2009 #6

    Wax

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    Here you go. Look at the carbon directly connected to the -OH group. It has four completely different things connected to it.

    R-butan-2-ol-2D-skeletal.png
     
  8. Jun 29, 2009 #7
    Isn't it just connected to two other carbons and an -OH?
    EDIT: Oh, and a hydrogen, haha.

    So where does the Stereochemistry come into play then?
     
  9. Jun 29, 2009 #8

    Wax

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    Stereochemistry are those dash lines, it just means that the -OH group is not on the same plane. If you were to lay that compound on a surface, the -OH group would be sticking out at you while all the carbons would be laying flat on the table.
     
  10. Jun 29, 2009 #9
    So what exactly was the correct answer to the #2 post in this thread then?

    Also, what is the "stereocenter"?

    Thanks.
     
  11. Jun 29, 2009 #10

    Wax

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    I answered the number 2 question in my first post. Try reading it carefully.

    A stereocenter is a point in the compound that creates two completely different molecules. Here is the other molecule of that compound I just posted. In this case the -OH group is pointed up, the last case the -OH group was pointing down. They are two completely different compounds and they are named differently.

    S-butan-2-ol-2D-skeletal.png
     
  12. Jun 29, 2009 #11
    So in this case, the Stereocenter would be the Carbon the -OH is attached to, since that's the point that differs between the two?

    Are the 4-sides you are referring to the Carbon and -OH and two H's?

    What if you're only given 1 diagram and asked to indentify the sterocenter?

    Thanks.
     
  13. Jun 29, 2009 #12

    Wax

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    First question. Yup.


    Second question. Nope. You have to look at the whole group. In that last picture there are 4 completely different groups attached to the carbon. -OH, -CH3, -CH2CH3, and a -H.


    Third question, you wouldn't be asked asked that on an exam. It would go deeper then that. Granted that you are taking Organic Chem for majors.
     
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