Sciencemadness Discussion Board

Leuckart reaction and acyloins (particularly L-PAC)

Jesse Pinkman - 28-8-2012 at 13:06

Hello members of my favourite chemistry forum, I browse the forum for years, but now I have decided to register. Some of the members are truly my idols, they are "El magico" like Heisenberg on series Breaking Bad.

Now on the topic: I was searching on alternatives of the Al/Hg reductive amination of L-PAC, particularly interested in the Leuckart reaction, but I haven't seen a post or a paper if the Leuckart reaction is working on acyloins like L-PAC.

I have found a paper by Smith, Kline and French Laboratories, in which on page 312 it is written, that "benzoins behave abnormally with the Leuckart reagent".
Because benzoins are a form of acyloins, i was wondering if L-PAC will behave abnormally and undergo a cyclisation in the Leuckart reaction, not yielding the desired amino compound.

Of course one can protect the hydroxyl group but this complicates the amination.

Many thanks in advance for your responses !

Attachment: leuckart.pdf (710kB)
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kristofvagyok - 28-8-2012 at 13:31

Quote: Originally posted by Jesse Pinkman  
Now on the topic: I was searching on alternatives of the Al/Hg reductive amination of L-PAC, particularly interested in the Leuckart reaction, but I haven't seen a post or a paper if the Leuckart reaction is working on acyloins like L-PAC.

I have found a paper by Smith, Kline and French Laboratories, in which on page 312 it is written, that "benzoins behave abnormally with the Leuckart reagent".


I would suggest to find a bit more interesting and less harmless part of chemistry than making aint so legal things with basic reactions -what won't work in this case.

Also. Here is something interesting for you:
Journal fuer Praktische Chemie (Leipzig), 1890 , vol. <2>41, p. 327

Lambda-Eyde - 31-8-2012 at 08:31

Quote: Originally posted by kristofvagyok  

Also. Here is something interesting for you:
Journal fuer Praktische Chemie (Leipzig), 1890 , vol. <2>41, p. 327

Seeing this aroused my interest, so I tried to check it out - but if I understand the German correctly, you have provided the wrong page number. "Einwirkung von Ammoniumformiat auf Benzoin" appears on page 333 in the article "Ueber die Einwirkung von Ammoniumformiat auf Ketone" written by mr. Leuckart himself. DOI: 10.1002/prac.18900410121

Uploaded for those who can read German.

Attachment: Ueber die Einwirkung Ammoniumformiat auf Ketone J.Pr.Chemie 41 1890.pdf (486kB)
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zed - 12-9-2012 at 12:59

If you had some L-PAC, it could easily be reduced to the diol.

That diol could then be refluxed with dilute Sulfuric Acid, to yield P2P.

Jesse Pinkman - 25-9-2012 at 09:48


Quote:

If you had some L-PAC, it could easily be reduced to the diol. That diol could then be refluxed with dilute Sulfuric Acid, to yield P2P.

I'm interested in ephedrines, not in Phenyl-2-Propanones

But for those interested in P2P : The same fermentation which produces L-PAC, can also produce the diol, then a simple Pinacol rearrangement will turn it into P2P

Here is the reference:

Attachment: diol.pdf (831kB)
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