Provide the mechanism and final products for the following reaction. You may skip the tautomerization mechanism if one is required. Cool. So first of all, what are we even dealing with here? Well, all I really see for sure is that I do have an Allyl ether here, so I have an Allyl ether. Another thing I noticed is that my double bond is not conjugated with any other double bond so I'm just going to put here it's not conjugated and I'm reacting with heat. So what this tells me is that this must be a Claisen rearrangement. Remember a Claisen rearrangement can be more technically defined as a 3,3 Claisen rearrangement. That is going to help us determine which bonds to make and which bonds to break.
So just so you know guys, like common sense tells you it's a Claisen because it's on the Claisen topic, but I'm trying to help you think, coach you through how you would see this if it was in the middle of 40 other reactions on your exam. That's how you would distinguish that this must be a Claisen. Okay? Cool. So what else do we need to do? We must rearrange this because, and not just rearrange, we must rotate and then we can rearrange. We must rotate because we need the double bonds to face each other. So in this case what we're going to do is we're just going to rotate this guy up. So let's redraw it here, O, and now let's put the double bond right here. And now we actually can start to visualize these 2 double bonds coming together and making a single bond in between them. This is the way you would rotate it so that you could visualize the Claisen rearrangement.
Now something else to be aware of guys is that remember that I told you that the bottom part of the allyl ether always stays the same, but the top part might change. So this is an example, the top part is different than the other example we did. The other example was a vinyl ether, but specifically, the top part is what we call a phenyl ether. Not phenol, phenyl is different. Phenyl ether because it's directly attached to a double bond, which is fine too because we can use that double bond inside of the aromatic ring to do our mechanism.
Cool. So guys, what's going to happen? Remember this is a 3,3 Claisen rearrangement and we have to break a bond and make a bond. Maybe the most obvious one is the bond that we're going to make, we know that we have to make a new bond here because that's the only area that's missing a gap, which means that this is the 3 and this is the 3. That being said, that means we can count backward and figure out what the one positions were. This is my 2 and this is my 1, this is my 2 and this is my 1. And guys what this means is that I am now ready to break bonds and make bonds using my mechanism. So what I would do is move my electrons here and then move these electrons here and then move these electrons here. And what that's going to do is it's going to give me a new structure that looks like this:
So this appears to now be a carbonyl. This is now a single bond. This is now a single bond. This is now a double bond. That methyl group is still there and these O bonds didn't change. And there you have it, we just broke the bond between the ones and then we made a new bond between the threes and we just did a Claisen rearrangement. Cool? So are you guys happy? Makes sense? Did I miss anything?
Guys, I missed something. We're not done yet because this happens to be the one unique type of tautomer that prefers to be an enol because it wants to be aromatic and turn into a phenyl with an OH. So that means that if you, it says you may skip the tautomerization mechanism if one is required, but I still need to write that it's going to tautomerize. So let's go ahead and do this with equilibrium arrows. Let's write tautomerize. Just so you guys know, in this question it says you can skip it, but almost all professors in all textbooks will not make you draw the tautomerization step for this reaction because it's not the point of this reaction. We have a whole chapter about tautomerization chemistry that you can you can learn about that mechanism if you want, but the point of this, this is a pericyclic reaction, is just to understand that tautomerization will take place. So my final final product would be this with double bond, double bond, double bond, OH and then single bond, single bond, double bond methyl group. Cool and you don't have to draw it just like that, you could also have drawn it sticking out and that also would have been fine. Cool and there you have it guys, we are done with the Claisen rearrangement mechanism. Alright, great. I'm sorry I said Claisen condensation and I meant Claisen rearrangement. Okay. Awesome guys. Let's move on to the next video.