Ochem help- Robinson Annulation

[jmcfa002]

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I'm in my second quarter of ochem, and I'm studying the "robinson annulation"

I'm having a hard time with it, does anyone have a good way of explaining it?

Thanks

 

[OrllY]

I'm in my second quarter of ochem, and I'm studying the "robinson annulation"

I'm having a hard time with it, does anyone have a good way of explaining it?

Thanks

Michael + Aldol.
just look for those acidic hydrogens and see what you can do with them.

 

[AbsoluteEthanol]

Michael + Aldol.
just look for those acidic hydrogens and see what you can do with them.

couldn't have said it better myself! occam's razor at its finest here!

p.s. i could never understand why people ask chemistry/biology questions on SDN. Is this seriously your main resource when you have a problem you cannot solve? i should hope not!

 

[jmcfa002]

No, its not my main source. I studied it for about 20 minutes today and couldn't figure it out, and I'm going to school tomorrow to get help. I've been studying it and trying to figure it out better before I go to ask for help. I was thinking that someone may have an easy way to do it.

I don't know Michael's addition, so maybe that is the problem.

 

[ExpressMaiL]

The annulation is a great reaction.

 

[OrllY]

i may have written a paper on this...

 

[Sparda29]

i may have written a paper on this...
http://docs.google.com/Doc?id=dqh7jxm_119dncr4tgn
i don't have office anymore so had to use google documents...
ENJOY!

Are you serious? Just download BitComet, and then go to PirateBay and download any cracked version of office.

 

[jmcfa002]

or use open office, it can do .doc

 

[rycetrix]

I'm in my second quarter of ochem, and I'm studying the "robinson annulation"

I'm having a hard time with it, does anyone have a good way of explaining it?

Thanks

Robinson Annulation...I just taught my students how to do this so yea..(I am a tutor)

So here we go:

It is as some people have stated above, it is a Michael followed by an aldol. A Michael addition is basically an enolate + an alpha, beta-unsaturated carbonyl. The enolate adds to the double bond of the alpha, beta-unsaturated carbonyl. The product of Michael reaction is a 1,5-dicarbonyl compound. The aldol part is basically the Michael product undergoes an intramolecular attack. This is performed by making an enolate on part of the Michael product, and then it will attack the other carbonyl since this is a dicarbonyl compound (2 carbonyls). And then the molecule will undergo aldol condensation to get the desired product, which should have an alpha, beta-unsaturated carbonyl in it. And that would be the Robinson Annulation product.

It is quite hard to describe the reactions without actually showing you what is going on.

Let me know if this helps.