[SirRoderick]

Hi, I'm a Chemistry student currently in my second year at University of Hasselt in Belgium and I'm having a little problem. I'm currently working on a sort of project in which we basically have to synthesise certain compounds that are currently being researched in relation to "click" or building block chemistry. Now I'm having some trouble finding a proper way to get these two reactions to make sense. (Please read all of the following text as well)



Now the first reaction I'm being told, by the research assistent, is a Beckmann rearrangement. However, I can't see how this is possible. As far as I know that reaction results in an NH group replacing the NOH, shifting the carbon bond as well as an extra double-bonded O. In this case we end up with retaining the NOH group, removing the O and creating a ring structure. I would be very grateful if someone could explain the reaction process in this case.

The second reaction on there appears to be a condensation reaction with Ph-N=O. Now I'm having trouble with the details of this. Presumable the double bond electrons "fall back" onto the adjacent carbon, bordering the N, thus creating a + charge which Ph-N=O can react with, but I'm not sure about this at all. I'm entirely not sure on the following rearrangement of the charges. In what order do I form the the new double bond and remove the hydrogen from the OH group?

Anything else I'm missing/should know?

I would also like to add that while I normally appreciate the approuch of gently nudging me toward the correct awnser until I figure it out myself, I am a bit short on time here. So I would be VERY grateful for a more complete awnser here. Any required reagents or reaction conditions would also be very appreciated. That said, if you don't have a complete explanation please do still post any relevant ideas. It's all helpfull!

Thank you very much for your time.

[orgopete]

On the first reaction, is that structure correct? It makes more sense if the there is an OH at C3. In a Beckman rearrangement, it is a dehydration-rehydration reaction. The same MF is present in the product as the starting material. In this instance, it is a net deoxygenation. Sulfuric acid does not normally do that. I think a mechanism can be drawn with a C3-OH group.

[SirRoderick]

On the first reaction, is that structure correct? It makes more sense if the there is an OH at C3. In a Beckman rearrangement, it is a dehydration-rehydration reaction. The same MF is present in the product as the starting material. In this instance, it is a net deoxygenation. Sulfuric acid does not normally do that. I think a mechanism can be drawn with a C3-OH group.

See that's the proble I'm having. I'm being assured that sulphuric acid WILL do this and that it is a "variation" on a Beckmann rearrangement.

Now I have figured out the second one. Use NaEtO to activate that spot and the condensation will happen.