Schleimsäure
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Nomenclature Positions
Can't find the right text passage. How was the numbering of postions in poly ring systems done again?
In 2,3,7,8-Tetrachlorodibenzodioxin the chlorines are in postions 2,3,7,8.
If one starts at the top Carbon of one benzene-ring I don't get how you come up with 7 and 8.
It would be 2,3,9,10 if you go in a straight line.
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Alice
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This may help: http://www.acdlabs.com/iupac/nomenclature/79/r79_72.htm
Atoms being part of more than one cycle aren't counted (usually omitted, as you can see there is a way numbering them too).
| Quote: | | The system thus oriented is numbered in a clockwise direction commencing with the carbon atom not engaged in ring-fusion in the most counter-clockwise
position of the uppermost ring, or if there is a choice, of the uppermost ring farthest to the right, and omitting atoms common to two or more rings.
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[Edited on 24-5-2017 by Alice]
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Schleimsäure
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Thank you very much, that's it.
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Alice
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You're welcome. Nomenclature can be a real pain...
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Schleimsäure
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Oh ja, especially if you're just an amateuer like me with an academic background in business admin
I watched some Organic Chemistry I and II on youtube from German Ruhr-University:
https://www.youtube.com/watch?v=HE6m7LYS3D4
The whole OC lecture there (over 100 lectures from Prof. Dyker).
Also shows how demanding a complete chemistry course is.
[Edited on 24-5-2017 by Schleimsäure]
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