steps to drawing enantionmers

[psychme]

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what are the steps to draw the enantiomer of this:

http://upload.wikimedia.org/wikiped...tructure.svg/700px-Naproxen_structure.svg.png

this is the S-isomer of Naproxen. How do i draw the R isomer??

 

[ilovemcat]

what are the steps to draw the enantiomer of this:

http://upload.wikimedia.org/wikiped...tructure.svg/700px-Naproxen_structure.svg.png

this is the S-isomer of Naproxen. How do i draw the R isomer??

I'm not absolutely sure about this. I'm a little rusty with Organic:

Try assigning priorities as is first.
#1 - Carboxyl Group (OOH)
#2 - Cyclic Group attached to Carbon (CCC)
#3 - Methyl Group (HHH)
# 4 - Hydrogen

Before finding the rotation, you need to swap the Hydrogen with the Methyl Group because the lowest priority group (Hydrogen) must always point into the page (where Methyl currently is). Once you've done that, find the rotation of priorities 1,2, and 3. We see that the rotation is clock-wise (R)- but because we swapped substitutes, this isomer is opposite of that making it the (S) configuration for this molecule.

 

[Rabolisk]

Simple, actually. You just draw a mirror image. For example, you can draw everything to the right as being to the left. That is, you swap right-left, but not above-below the plane or top-below. It's kinda hard to explain, sorry.

 

[psychme]

so the way i did it was make everything that is right on the S
isomer, left on the R isomer. Then i rotated the R isomer so that if i were to place the R isomer and S it would match up except for the substituents coming out of the plane of the paper (showing that they are nonsuperimposable).

correct??

I hate these kaplan section tests. i fail them so badly...

 

[Rabolisk]

Yes. Absolutely correct.

 

[Isoprop]

2 ways to draw EN:

1. draw a mirror image
2. convert all wedges into dashes and all dashes into wedges.