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Topic: Converting from Fischer projection to Wedge Dash?  (Read 19758 times)

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Offline spirochete

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Converting from Fischer projection to Wedge Dash?
« on: June 09, 2009, 03:10:32 PM »
I was never taught this in my organic classes and I'm trying to teach it to myself now.  My text (wade) totally glosses over this topic and jumps straight to chirality issues like finding planes of symmetry which is quite obvious to me anyway.

I can convert easily when the molecule has just one or two chiral carbons, so i understand the basic concept.

With more carbons my strategy is to flip the molecule on it's side and draw the straight chain in the conformation of a ring. then unfold to the straight chain because this is the only way I can think to maintain every vertical line as a "dash" when converting to wedge/dash.  I would like a better system though because straightening out long rings with many stereocenters gives me a headache.   Maybe I just need a better system for unfolding rings?

Anyone know of a website with practice problems and/or explanation for this?  I would really like some practice problems with answers to test myself.

Offline azmanam

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Re: Converting from newman projection to Wedge Dash?
« Reply #1 on: June 09, 2009, 03:14:48 PM »
here's an explanation of how I do it.  I don't know of any websites.

http://www.chemicalforums.com/index.php?topic=31388.0
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Offline spirochete

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Re: Converting from newman projection to Wedge Dash?
« Reply #2 on: June 09, 2009, 03:18:57 PM »
wow I really have issues with writing newman when I mean to write Fischer.  Newman projections I can definitely do fine. . .meant to write fischer.

Also this could be moved to non graduate if anyone cares.

Offline azmanam

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Re: Converting from Fischer projection to Wedge Dash?
« Reply #3 on: June 09, 2009, 03:25:08 PM »
and another example of how I walk through it.  still don't know of any websites :)
 
http://www.chemicalforums.com/index.php?topic=32203.0
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Offline azmanam

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Re: Converting from Fischer projection to Wedge Dash?
« Reply #4 on: June 09, 2009, 03:27:18 PM »
a more general explanation of how I rotate wedge/dash from one view to another.

http://www.chemicalforums.com/index.php?topic=28328.0
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Offline Dan

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Re: Converting from Fischer projection to Wedge Dash?
« Reply #5 on: June 10, 2009, 04:47:47 AM »
I would like some practice problems with answers to test myself

Draw these sugars in wedge/dash, and in their cyclic hemiacetal forms (furanose and pyranose). You should be able to check your answers with google, or post here and I (or anyone else) will check them.
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Offline spirochete

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Re: Converting from Fischer projection to Wedge Dash?
« Reply #6 on: June 10, 2009, 02:31:50 PM »
Thanks, I am getting the hang of it now.  Don't know why I didn't think of just looking up the basic sugars online.

 I'm still interested in any random tips or tricks people have for doing this.  I may TA an organic class next semester so it's always nice to have multiple ways of doing it for teaching purposes.

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