Baeyer-Villiger Oxidation

What's up? Everybody in this section, we're gonna take a look at an oxidation reaction that is very unique, but also very useful. Okay, it's the bare Villiger oxidation reaction and the bear Villiger oxidation reaction reacts Alba hides or key tones with proxy acids, all right. And it turns the key tones into Esther's and how the hides into carb oxalic acids. All right. And like I said, it's reacting with proxy acids. Where have we seen proxy acids before? Yeah, proxy acids are our IP oxidation re agent when we're making an epoxy died from an AL Keen. Okay, so remember, we can have some sort of all keen plus our proxy acid, and we'll get in hip oxide like that, that little three member during with the oxygen. Okay, When we use the same re agents with an allied or a key tone, we get this oxidation reaction where we increase our number of bonds to oxygen. Okay, this reaction is unique in that, or it differs from our other oxidation reactions and that we can oxidize a key tone, which is usually the most oxidized weaken. Make something with, like, our Jones oxidation, which is our strong oxidizing agent, we can actually further oxidize a key tone. Okay, Uh, s Oh, that is really useful. Especially when we get into the carb oxalic acid derivatives chapter where it's really important to be able to go from Allah hides and key tones to carve oxalic acid derivatives. Okay, so this oxidation, it is regio selective, based on the migratory attitude of the groups that are attached to a carbon carbon. Alright, So migratory attitude is probably a new word for all of you and it's something we'll define once we get down to the General Reaction area. I even know it's basically just how well does one group are? How likely is one group to move compared to another group? Okay, that migratory aptitude trend is similar to the cat ion stability trend. Alright, there's really not a great way to memorize this, but hydrogen has the highest migratory aptitude. Alright, followed by tertiary than secondary carbons. All right, after that, we have arrows. So that's like our benzene rings are aromatics. And the worst is gonna be our primary carbon. Okay, so this is similar to our carbo Calyon stability trend, and I should say that this is relatively controversial. Still, what I have listed here is the most up to date in the most agreed upon trend. But you may see some variation from your professor or your textbook, alright. And just go with whatever your professor expects, you know, But it's most likely gonna be this. Okay, so now to get into the general reaction, All right, we start off with an Allied or a Quito, and we reacted with our proxy acid. In both of these reactions we use EMC PBA, right, Which is Metta Koro Proxy. Ben's OIC acid. And what this looks like is we have a proxy acid, right? This here is our proxy acid. And attached to it is a benzene with a meta chlorine. Okay, so that's r m c p b A. But really, all we care about is this proxy acid portion of it, alright? And what the reaction does is it basically inserts and oxygen between our carbon carbon and our group with the highest migratory aptitude. Alright, So, looking at the key tone left here, we have a primary carbon and we have a tertiary carbon directly attached to our carbon carbon. All right, looking back to our trend. Tertiary is has a higher migratory aptitude than primary. Alright, so that will be our group that migrates and what we mean by migrating or by our migratory aptitude, is we have an oxygen atom from our proxy acid that is essentially just going to insert between the cardinal carbon in the group with the highest migratory aptitude. Okay, so that group has to shift. It has to migrate away to make that new bond to oxygen and break the bond with the cardinal carbon. Alright, you'll see exactly why this is called migration when we get to the mechanism. Alright. But that is what our migration are migratory attitude is describing is which group can best separate from the carbon carbon and make that new bond to the oxygen. Okay, so here it's the tertiary group and that's what we end up with in our product. We have that oxygen inserted between our Carbonell carbon and our tertiary carbon. All right, looking at the next example, we have an allied this time, right? So we have a hydrogen compared to a tertiary carbon. Which group here has the highest migratory aptitude? Yeah, here it's the hydrogen. Okay, so now our oxygen needs to insert on that right side so that hydrogen is our group. That's gonna migrate. All right. And that's what we see here. We inserted our oxygen between our carbon carbon and are migrating group. Okay, Before we move on to the mechanism, we need to talk about stereo chemistry, All right? And the stereo chemistry for these reactions is really easy. All right? It just stays exactly the same. So, looking at this example, we have a key tone. Were reacting with M c P b again. All right, so we know we're doing our bear villiger oxidation, and we have a secondary carbon on the left side and a tertiary carbon attached carbon carbon on the right side. Which of those has the higher migratory aptitude? Yeah, the tertiary does. Okay, so that's the side. We're gonna insert an oxygen on, all right? That tertiary carbon migrate away, and we'll insert our oxygen here. And all we need to know about our stereo chemistry is that it stays exactly the same. Okay, so this was a wedge in our starting material, all right? It is gonna be a wedge in our product here. All right. And if we looked at our absolute configuration R R and s, it's gonna be retained as well. Okay, so now in the next video will get into the mechanism and really see where the word migration comes from, okay?

All right, everybody, let's go ahead and take a look at the mechanism for the bear. Villiger. Oxidation reaction. This mechanism takes place in three major steps. Two of those three steps. You should be very familiar with what you've been doing them the whole time, more or less that you've been in organic chemistry. Okay. And then there's just one new step, which is where we get the term migration from All right, and we'll discuss that when we get there. Okay? So starting off with the first step, this is one that you've done 1000 times. It is our pro nation step. All right, So in our pro nation step, we just protein ate the oxygen in our carbon eel. Okay, so we have a key tone. Were reacting with a proxy acid, right? That acid has an acidic proton. Those are gonna react together. And what we'll have is this oxygen. We use a lone pair to make a new bond to that hydrogen. We made a bond. We have to break a bond. So we kicked those electrons up to that oxygen. All right, That's all our pro nation step is, and that gets us to our first set of intermediates. Okay, We're missing some atoms and some charges on these intermediates. Do you know what we're missing? Yeah, well, we just pro nated are Carbondale. So we need a hydrogen there. Right? And what charge will I give it? Yeah, that will give it a positive charge. Okay, what about the oxygen that just lost that hydrogen? Well, now that has an extra lone pair. It's gonna have a negative charge. Okay, so now that we have our complete intermediates here, we're gonna do our second step. All right? Which is a nuclear Filic edition step. It's our nuclear filic addition. All right? And this is just like any other nuclear Filic edition you've done before. Where the negative charge off. Whatever our nuclear file is in this case, it's our What was our proxy acid? It's that conjugate base that attacks the partial positive charge of our carbon carbon. Alright, so we just have this area here. We do our nuclear Filic edition right there. We made upon. So we have to break upon. So that's what we'll do right there. Okay, that will get us to our next intermediate. And again we're missing a couple atoms or charges here. All right. Where are we missing something? Well, yeah, I remember. We added this hydrogen in our first step. Okay, this oxygen right here, that is the same oxygen from our carbon carbon. We've had the whole time. Okay, so we need to have a hydrogen there. Will it have a charge? It all. No, it won't. Right. Okay. And if we wanted to or locate all of the atoms from our proxy acid, we could say that these two oxygen's the carbon. You know, in this, our group are gonna be those two oxygen's, the Carbondale and the argument there. Okay, so this is the new step in the mechanism that you haven't seen before. And this is our migration step. Okay, So this is how we go from that molecule to our final product, and it's our migration. Okay, So that oxygen of our carbon deal that came from our Carbonell. Okay, the yellow one. It really wants to reform that carbon oxygen double bond. All right, so it's gonna do that. It's gonna use the lone pair, and it's going to reform that carbon oxygen double bond. Okay, now, here you would probably expect that the bond between the carbon and the green oxygen that came from our proxy acid, you'd expect that to break. But that's not actually what happens. This is where our migration occurs. Okay, so if we look at the two groups attached there, we have a primary carbon, and we have a true sherry carbon. Which of those has a higher migratory aptitude? Yeah, the tertiary does. Okay, So what we wanna do is we wanna migrate that group and the migration. What that looks like is this bond here that I'm coloring in green? Well, actually, break that bond, and we'll use the two electrons in that bond to move the whole group. Okay, so this group, the tertiary group with the higher migratory aptitude, will migrate to the oxygen from our proxy acid. Okay. So that one arrow right there is where we get the word migration. All right, from there, we made a new bond, so we need to break a bond. Okay, We're gonna break the oxygen oxygen bond, and that is just going to swing over and form another carbon oxygen double bond. All right. And again, we made a bond. We have to break another bond. So this carbon auction double bomb gets kicked up to the oxygen. All right, so in total are migration. Step just has four arrows, all right? And they all move in the same general direction. Okay, if we have it drawn how we have here, they're all moving from the oxygen from our original carbon eel all the way out to the oxygen from our carbon in our proxy acid. Okay, so four hours there and that gets us almost to our final product. All right, we still have this hydrogen right there. Okay, so we're still gonna have a hydrogen in this product right here. All right, So what is the last thing we need to do to make our final neutral product? Yeah, we just need to de protein eight. All right. You may remember that. I said there's three major steps. All right? This is not a major step, all right? This is just a deep throat nation. We're gonna have the everything highlighted in green over here is gonna come in. So we're gonna have our two oxygen's our carbon eel in our our group. Right? That has a it's gonna be one oxygen that has a negative charge on it. Alright, That is just gonna come in and deep protein it. Our Carbonell here, just like that. Okay, so we're gonna get a neutral final product. Plus, we're gonna get a byproduct of a carb oxalic acid with whatever our group was part of our proxy acid that we started with. Okay, so this is the mechanism for the bear Villiger. Oxidation. Remember, it's the three major steps pro nation nuclear, Philip, condition, migration. All right. And then the last thing we have to do is just deponent to get our major neutral product. Okay, go ahead and attempt the practice problems that are following this, and then we'll solve them in the next video.

Okay. This first practice problem was asking us to predict the major product formed from this reaction. Okay, so first things first, we just need to identify everything involved. All right? So are re agent here. That we have are starting material is a key tone. All right? And we're reacting that with this molecule here, F 3 cc 03 h. What type of molecule is that? Is it a proxy acid? Well, yeah, all right. And how do I know that? Well, any time we see this general structure here, the c 03 h attached to whatever on the left, that carbon. All right. This could be anything on the left there. Uh, whenever we see that, c 03 h, we know that it's gonna be a proxy acid. Alright. So anytime you see a molecule written out with co three h, you know, it's a proxy acid. Anytime you see something that just has c h, right. And again this that our group there, That could be anything. Whenever we see either of those, we know it's a proxy acid. Okay, so we have a proxy acid and we have a keto What type of reaction is it? Yeah, it's gonna be a bear. Villiger, Oxidation reaction. Okay, so now that we've identified what type of reaction it is, we've identified our re agents. What's the first thing we should dio? Yeah, well, we should just look at our key tone and look at each side of the key tone and identify which has the higher migratory aptitude. Okay, so looking at this key tone on the right side, we have this carbon here. What type of carbon is that? Yeah, it's gonna be secondary. Okay, then, on the left. Here we have this carbon. They're attached to our carbon carbon. What type of carbon is that? Yeah, that is a tertiary carbon. Okay, so now we need to think back to our trend for migratory aptitude. And what has a higher migratory attitude? A tertiary carbon or a secondary carbon? Yeah. Tertiary does. Okay, so we know that that is gonna be the migrating group. All right. And remember that we can just kind of shortcut this reaction by thinking of our oxygen from our proxy acid. Just inserting itself between the carbon you'll carbon and the migrating group. So we can think about that oxygen just getting pushed in there. All right, in pushing those bet tertiary carbon down and the carbon carbon up. All right. And the last thing we need to think about is the stereo chemistry here. What's gonna happen to that wedged method? Well, yeah, our stereo chemistry is retained. Okay, so it's just going to stay as a wedge. It's literally just gonna get pushed down. Okay? So when we draw our product for this, we have our Carbonell. All right, if we were to number of carbons, we would have 123456 So we're gonna expand that from a six member during to a seven member drink where we inserted our oxygen right here. All right, then we're gonna have the rest of our carbons in straw that in black clips. All right, so if we number these, we would have 1234 Alright. So where does our wedged metal go? Yeah, well, we numbered it the same. So it's still gonna be on carbon six. Alright. It's just gonna be one further away from our carbon eel. All right, so this is what our product will look like we expanded our ring. We retained our stereo chemistry and we migrated the group the tertiary carbon with the highest migratory aptitude. Okay, so go ahead and give this next question and try drawing out the mechanism, and then we'll solve that in the next video.

All right, This practice question was asking us to show the mechanism and predict the product for this reaction. Okay, so again, we first just want to identify our reaction and classify it. Okay, so we are reacting a key tone there on the left and on the right. Here we have this molecule. Do you know what it's called? Yeah, this is M C P B. A. Okay. And M C P B A is a peroxide acid. All right, we know that because of this section right here, this is our C 03 h. All right. And that is what we have in every proxy acid. And whenever we have that with a key tone or even within Alba hide, we're gonna do our bear Villager oxidation. Okay, so now that we figured all that out, the first thing we should do for a question like this is just go ahead and predict the product. Okay, Bear villiger. Oxidation reactions are pretty easy to predict the product because we just have to insert oxygen. Okay, so we need to look at our key. Tom. All right, we have our carbon carbon here. We have a secondary carbon there. All right. And then we have this group over here, which is our arrow. All right. Does an arrow or a secondary carbon have a higher migratory aptitude? Yeah, these secondary carbon does. Okay, so that is the group that we want to migrate. So remember, we're just gonna think about inserting an oxygen in between dot carbon carbon and dot secondary carbon there. Okay, So what that would look like as a product? Because we would still have this aromatic ring. We would still have our Carbonell right now we just insert our oxygen. Okay, So we'll have a new bond from our carbon carbon to our oxygen and then a new bond from that oxygen to our secondary carbon just like that. Okay, so if we were to a number of these carbons, I would be one and two. This is carbon one and two. All right. We just inserted the oxygen there. We know that is our product. Alright. Now, for the mechanism, we just need to recall that it has those three major steps. Do you remember what those three major steps are? Yeah, we have pro nation nuclear Filic Edition. Then our migration step Okay. So in our pro nation step, what do we dio? Yeah, In our pro nation step, we just protein ate our carbon it Okay, so I'm going to redraw r M c P b A over here? Yeah, like that. All right. We use the hydrogen of our C 03 h two pro, Nate. Okay, so our oxygen makes a bond to that hydrogen. We made a bond. We have to break a bond. So what we're left with is our original group here and now we just have an oxygen with a positive charge. Okay, so that is our first step. That is our pro nation step. All right. In our second step, what do we dio? What's the second step called? Yeah, this is our nuclear Filic edition. Alright. And here we do we add our proxy acid that now has a negative charge to our carbon. You Okay, so this has a negative charge now, all right? It still has this benzene with the meta chlorine that negative charges attracted to the partial positive charge of our carbon carbon. Because we make a bond there and we break a bond, and that's our nuclear Philip conditions up. Just those two arrows. And what we get as a product is we have all these black carbons here are coming from our starting material. Okay, so now we don't have in carbon, you know, we have just a o. H. And we have our Ethel attached there. Okay, now we have this new bond, which I'm gonna show in green to our red oxygen's. All right, so this is our next intermediate, all right? And this is where the new step comes in for the bear. Villiger. Oxidation, right. This is where our migration step comes in. And what this looks like. This is our migration. Remember, we start at the oxygen that originated on our carbon eel. Okay, so if we trace this oxygen back through our intermediates, it starts out as our carbon eel oxygen. And what we do is we re form that Carbonell, that carbon oxygen, double one. All right. And then we have our migration step occur right here. Okay, so we already decided that that Ethel, that secondary carbon has a higher migratory aptitude compared to the Aral Group. The benzene on the left. So we're gonna migrate that Ethel all right. This bond I'm gonna draw in green here is the bond that will migrate. And what we'll do is we'll just migrate that bond, those two carbons to the oxygen from our proxy acid. All right, we made upon. So we need to break upon. So this oxygen oxygen bond breaks and swings over, making another carbon oxygen double bond that breaks this carbon auction Delavan and kicks the electrons up there. Okay, again, This step, Our migration step has four arrows total, and they all move in the same direction. Okay, here, we're going from left to right. That gets us something that's very close to our final product. Let's draw this in black. So we saw this benzene, right? We reformed our Carbondale. What's attached to that oxygen? Yeah, it still has this hydrogen attached. Okay, so that tells us is gonna have a positive charge. All right. We just broke this bond here, alright? And moved it over to the oxygen so that carbon eel just has this green bond to that oxygen. All right? Which in turn, has a new bond to our two carbons of the Ethel. Alright, Again, If we wanted to number those we could say This is carbon one. And this is carbon to this would be carbon one. This would be carbon too. Okay, so that's basically our final product. The last thing we have to do is just neutralize it. Okay, so we need to Deep protein ate that proton. And what do we need to use for that? Yeah, we just use the car Boxley that we just formed. All right, so all of this right here just ends up looking like this. So a car box, a concrete base of a carb oxalic acid, which is a car box late. All right. And we just use that negative charge of the car. Boxley, too. Deep protein ate the proton on our Carbondale. All right, so that is the mechanism for this bear Villiger. Oxidation reaction. All right. Remember the three major steps pro nation nuclear Filic edition and migration. Okay. And remember that that migration step has four arrows. It will always have four arrows and they'll always go in that same direction. Okay, let's go ahead and move on to the next section.