From: Lakshmipathi Pandarinathan (plpathi$##$hotmail.com)
Date: Wed Oct 12 2005 - 15:13:55 EDT
Jonas
1,2-diaminocyclohexane forms salt with tartaric acid (internal di salt) =
and precipitates out from solution. The selectivity is based on the =
matching 1,2- trans diol with 1,2-diamino compound. You may find more =
info in the latest paper ' Tetrahedron: Asymmetry 14 (2003) 2763-2769'
Pathi
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Subject: Everybody Digest, Vol 13, Issue 6
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> Today's Topics:
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> 1. aspartame analysis in chewing gum (anish ganesh)
> 2. Resolution of 1,2-diaminocyclohexane (JONAS SUNDBERG)
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> ----------------------------------------------------------------------
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> Message: 1
> Date: Tue, 11 Oct 2005 09:54:08 -0700 (PDT)
> From: anish ganesh <anishganesh$##$yahoo.com>
> Subject: ORGLIST: aspartame analysis in chewing gum
> To: everybody$##$orglist.net
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> Hi friends,
>
> I want to discuss you and get your opinion about the aspartame =
analysis. We are following the procedure of British standard for the =
aspartame analysis and it is applicable to food samples like jam, =
preservatives, marmalad, yoghurt, jelly, fruits...actually we applied =
exactly the same procedure for doing the analysis in chewing gum and =
found different result every time. So, when we checked the solubility of =
the product in BP, it is clearly highlighted that aspartame solubility =
is depending on pH and temperature and sparingly soluble. Whereas the =
standard aspartame what we taken is highly soluble in hplc water. How =
can this be highly contradictory?.
>
> So, as per BP method, we have done the perchloric acid titration for =
determination in the chewing gum also. But we are not getting correct =
result, against the additon of 3500ppm, its giving only 2200ppm. When I =
checked the production department for information about coating, I got =
the feed back that the temperature they employing is only 22 degree =
celsius and whole production is in air conditioned zone. and the intial =
conversion of aspartame to fluid is done with gum arabic. So there is no =
possibility of degradation to diketo piperazine.
>
> Can any one help me to do the aspartame analysis correctly?.
>
> Waiting for your suggestions,
>
> Regards,
> anish
>
>
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> Message: 2
> Date: Tue, 11 Oct 2005 20:18:34 +0200 (CEST)
> From: JONAS SUNDBERG <gussujon$##$student.gu.se>
> Subject: ORGLIST: Resolution of 1,2-diaminocyclohexane
> To: everybody$##$orglist.net
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> Hi!
> I need the mechanism for resolution of racemic 1,2-diaminocyclohexane =
using L-(+)-tartaric acid.
> It's for a report for a student lab we did, but I can't find any =
information about the mechanism and I've searched journals, textbooks =
and Google. Any pointers and tips are appreciated!
>
> /Jonas
>
>
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