jim (Hive Bee)
10-02-01 12:11
No 219506
      A question on peracid method  Bookmark   

Let me propose this-

Put the alkene in acetone, add the acid, and add the H2O2 with a mild base mixed with it, like NaCO3.  Would this work?  Would this buffer the solution slightly, and form the epoxide instead (which is alright by me)?  Please send some feed back.
 
 
 
 
    Chromic
(Hive Addict)
10-02-01 21:17
No 219700
      Re: A question on peracid method  Bookmark   

From what I've read of the reaction mechanism, the answer is yes if the pH is kept neutral or slightly basic. Are you looking for a reference?
 
 
 
 
    Chromic
(Hive Addict)
10-02-01 21:34
No 219706
      Re: A question on peracid method  Bookmark   

I went and dug up the ref anyways. The answer is yes, use DCM and peracetic acid buffered with sodium bicarbonate. Form the epoxide, and have fun. See Organic Syntheses, CV 5, 414
 
 
 
 
    jim
(Hive Bee)
10-02-01 22:30
No 219723
      Re: A question on peracid method  Bookmark   

How about this:

There are some detergents that contain sodium percarbonate ( in relatively large %-ages), which upon addition to water form H2O2 and sodium carbonate, in a 1 to one molar ratio ( i think, maybe slightly higher).  This would be an easy way to get high concentrations of H2O2.

Perhaps this could be another alternative to H2O2, and sodium perborate.
 
 
 
 
    Chromic
(Hive Addict)
10-03-01 13:46
No 219956
      Re: A question on peracid method  Bookmark   

Think about the nasty emulsions that would form. I'd stick to the buffered Oxone, peracetic or performic methods.

Does anyone have any details on reducing the volume of acetic acid needed?
 
 
 
 
    PoohBear4Ever
(Junior Service Representative)
10-03-01 14:08
No 219966
      Re: A question on peracid method  Bookmark   

Look at experimental in Post 219711 (PoohBear4Ever: "Re: Isomerization/Peracetic Oxidation", Newbee Forum) and tell me what you think.

PB
 
 
 
 
    Semtexium
(Hive Elder)
10-03-01 14:40
No 219973
      Re: A question on peracid method  Bookmark   

SWIM just got some mail and from the sounds of it that peracetic in DCM is some wierd assed shit.  While it looked like there was a fair yeild of ketone, ketone doesn't act like this in the freezer.  Ketone SHOULD stay very fluid, not gel up like this supposed ketone does...  When I hear more I'll let you know...

P.S. The peracetic as written up in Rhod's review WORKS, without a doubt, infact some of the most potent shit SWIM's ever done.  Although I honestly think that is because he's got a nice crystalization tech down and ALWAYS re-xtalizes rather then having anything to do with the ketone... wink

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