From: Luis Fernando Garcia Alles (luis.garciaalles$##$ibc.unibe.ch)
Date: Tue Oct 10 2000 - 10:55:37 EDT
Dear People,
my problem is as follows: I'm trying to obtain a derivative of acrolein or
acryladehyde [RO-C(=CH2)-COH] by oxidation of the corresponding primary
hydroxyl group to the aldehyde, using CrO3/Py. I can see by TLC that the
product is presumably cleanly formed, but after removal of the catalyst by
filtration on Silica I recover very small amounts of the compound (<5%).
Whether the bad yield is due to the purification or to problems during the
reaction -polymerization?- is not known. Furthermore, the isolated product
decomposes to give another compound which does not move on TLC under the
same elution-conditions.
Of course, one of the possible explanations might be that the
polymerization of the compound is taking place. I've checked in the
literature and it might be rather likely. If this is true I might try to
stabilize the derivative once purified by adding hydroquinone. But what can
I do to increase the yield of the reaction (I cannot add this reductor to
the CrO3/Py solution)??.
Any help will be very appreciated.
Thanks in advance!!
=====================================
Luis Fernando García Alles, Ph.D.
Departement für Chemie und Biochemie
Universität Bern
Freiestrasse 3
CH-3012 Bern, Schweiz
Tel. ++41 (0)31/631 37 92
Fax ++41 (0)31/631 33 83
E-mail :garcia$##$ibc.unibe.ch
=====================================
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