ozonolysis in the presence of PMB

AV · Joined: 04 Jan 2007 Posts: 6

pMeO-benzyl group (PMB) is relatively senstive to ozone. Nevertheless, normal C=C could be selectively cleaved if to perform reaction at -78°C.
In our hands was important: after placing a flask into dry ice bath let stir for 20-30 min to ensure reaching -78°C. If we started ozonolysis earlier, PMB got cleaved as well.
(Private communication from T. Gaich, University of Vienna)

Guest · Posted: Mon Sep 10, 2007 1:46 pm Post subject:

just add one crystall of Sudan-Red to the solution and you will see when the PMB starts to get consumed...

Guest · Posted: Fri Nov 14, 2008 7:38 pm Post subject:

Which sudan red dye do you use: sudan red III or sudan red 7B?

Henry · Joined: 13 Nov 2007 Posts: 12

afaik does the type of sudan red not matter.

good luck