Understanding Aldehydes and Ketones

Welcome back. Chapter 6 is aldehydes and ketones, which are formed by the oxidation of... alcohols, which are formed by the oxidation of general compounds, right? So in organic chemistry, if you take a basic hydrocarbon structure and you oxidize it, you can turn it into an alcohol, and then turn it into an aldehyde or a ketone. You might turn it into an acid, and you might even turn it into carbon dioxide, right? You're going up the oxidation ladder. And that's the way they actually structure these chapters as well. They go up the oxidation ladder. It's just that no one ever told you that. And now I'm holding your hand through it, right? So we talked a little bit about... So naming different ketones and aldehydes, stuff like that. When it's not the highest priority, it's oxo. When it is the highest priority on a ketone, it's one, O-N-E, like butanone. And then in aldehyde, it's butan-al, right? Cool. So the first thing is nucleophilic addition reactions to ketones and aldehydes. So... I'm going to talk to you about hydrate formation. So if we have an aldehyde, acid aldehyde, and we put it in a solution of acidified water, we can observe a protonation of the carbonyl oxygen That will swiftly be followed by attack of the labile carbonyl carbon. And in order for the... Sorry. In order for the reaction to propagate, it is more than likely, or just for the simplicity of the reaction, we write that this gets deprotonated by another one of these starting material in order to perform the first step of the next reaction. Right? So we see the carbonyl carbon coming, grabbing that, and we get, when in reality, it's probably the solvent that's coming in to do this. And it's going to make another H3O+, and then that's going to protonate another thing like this, blah, blah, blah, right? And then we get something known as a hydrate. I will quite literally, let me make sure I'm naming this properly. I am. I will give five dollars to anyone who can tell me what type of molecule that is, other than a hydrate. What type of dial? There's two types of dials. This is a specific one. I can't give you any more hints than that. That's coming next. That's reducing sugars. We'll talk about that in a second as well. This is called a geminal dial. A geminal dial. Which is different than a vicinal dial. A vicinal dial looks like this. And it's what you create when you react a double bond with OSO4. A vicinal dial. That is a vicinal dial. How do you remember geminal and vicinal? I always thought that this little two-spoke thing and the circles look like a gem, like little diamonds on top of spokes. Geminal and vicinal means they're just in the same vicinity of one another. They're not on top of one another. They're just in the same neighborhood, right? Geminal and vicinal dials. Like the pinnacle rearrangement begins with a vicinal diol. So a vicinal diol, otherwise known as a hydrate. And this is an aldehyde hydrate because there's an H right there. To make a ketone hydrate, the same exact thing. If you don't wish to copy this down, you don't have to because it's literally the same thing that we just did. I'm doing it for the sake of completion. Geminal dial from a ketone because there's no H over there. Good? I'll give you a second. I get tired up here sometimes. We should throw a party our last day here. No, like when I leave you guys on your own and you never see me again ever. Oh my god, no. Huh? You can finally clap on that day, yeah. Oh no, I'm coming back next year. And the next year, and the year after that. Yeah, I'll see you guys all the time, don't worry. I mean, I'll see you guys. I might see a couple of you guys at medical school. Who knows? I'm sure a couple of you will come to Downstate. Here's hoping. What's the Downstate MCAT average for my class? 5.16. 5.16. We have nine people who scored above a 5.20, and I'm one of them. In a class of 230, I think. But, Downstate loves to take kids from Brooklyn. So, roll your dice and do well. Both. Roll your dice, do well, stay consistent, and focus when I'm teaching. We talked about... hydrates and you brought up a very good term. What did you talk about in a second go? Hemiacetals and acetals. So it's basically the same thing. And the acet, like the al ending, right? Al means we're working with aldehydes mainly. This mostly happens with aldehydes. So hemiacetal slash acetal. Hemiacetal, acetal, right? So this is when we, instead of water, we use alcohol. So we get protonation. Protonation of the carbonyl oxygen by the protonated solvent, correct? We have a reversible process which creates this. We will get ROH, now a good nucleophile because this is primed for attack, to attack there. And we get O, R, H, and OH. And deprotonation of this by the solvent yields... H-O-R-O-H. O-R and O-H on the same carbon means what? Means acetal. Sorry, sorry, hemiacetal. It's half. Hemiacetal. Half an acetal. Hemiacetal. Half. Half of what? Well the OR is what makes it an acetal. So it's half of that. If both of them were OR it would be an acetal. One of them is an OR, it's a hemiacetal. So how do we make a full-blown acetal? We take that and we keep reacting it. And now this is where people start to get lost. Because it doesn't look like that's going to keep reacting. But it will. Because... You have this, O-R-O-H, and instead of protonating the O-R and going backwards, why don't we protonate the O-H and see what happens? So, R-O-H2 plus will protonate the O-H and make another molecule of R-O-H on the side along with O- R and O H2. And now that that's a good leaving group, instead of making the carbocation, let's do a very famous biochem move, very famous upper-level orgo biochem move called assisted leaving. Not assisted living. Assisted leaving. Where the electrons here kind of give this guy the boot. Hey, fuck off. Get out of here. You're already a good leaving group. Get out of here. Right? So that guy gives that guy the boot, right? And we get... Wow. That, that's impressive. Why is that impressive? Because now, look back to the first reaction. We basically have the beginning step of the last reaction, but with an R instead of an H. That's incredible. That's really cool. That the solvent completely... Completely changed the way this is. Because normally, you can't get an R to attach to a carbonyl carbon like that. You can't. It's just not going to happen. Right? Unless the R was positive and somehow it got attacked and something like that. Plus, that's not, like, when you have this. Sorry, I forgot my H. When you have this, and if you had this, that's not even, like, negative enough to attack there. So it's so hard to do that, but now we just did. Right? We just did. And now you might be thinking, you know, well, we kicked off this water. Wouldn't the water just attack back right here? Isn't that what we've been seeing all this time? But you have to think. You have to think. When we do a reaction like this, the water came from where? It came from the beginning when we were working with this guy. The water is that. It's this oxygen that got protonated twice by the alcohol, right? So both those hydra... This is where your knowledge of... Atom tracking needs to come in. That water is, that oxygen is one of these original oxygens that got kicked off, and both those hydrogens came from the solvent. Right? You need to be cerebral enough to see that. And if you're not, it'll come with practice, I promise. Right? So why wouldn't the water just come back here? Well, we know that this water, that oxygen, came from the solvent. So, sorry, it came from the reactant. What do we have more of, solvent or reactant? The solvent is always in like 10,000, 100,000, 1 million time excess, right? So if we have one of these, we have a million of these. So which one's more likely to attack? The ROH. Fine. Done, right? H-O-R from there and O-R-H from the solvent. And now R-O-H solvent will deprotonate. Why does solvent deprotonate? Because there's so much more of it than everything else. And we get H-O-R-O-R. That is a full-blown acetal. Everyone clap for the acetal. Yeah, you made it. He's so cute. I love him. When it's with aldehydes, it's called acetal. When it's with ketones, it's called a ketal. Hemiketals and ketals. I'm not going to draw out the whole thing again. Replace the H with a CH3. Happens a lot more with aldehydes, though. They're more electrophilic than ketones are. Why? To further solidify our conversation, right? It has nothing to do with the SP2 character of whatever's going on, right? We know that these are both withdrawing groups, slightly negative and slightly positive, right? Slightly negative, slightly positive, slightly positive, right? Why is this more electrophilic than that? It has to do with the CH3 group on it, right? The H versus the CH3. Remember what I told you about R groups? R groups are donating. They donate some electron density onto there, so it decreases the electrophilicity of that carbon. Does that make sense? Good. You can explain everything. You can explain all of it. I promise you, you can explain all of it with very, very basic chemistry. If you remember a couple basic rules. Ummm... I like don't really like this one that much but we should talk about it because it'll come up every now and again just in nomenclature. Everyone put your pencils down. I do not want you to copy this. Just look. Look at it once. It's going to come up in your Anki. And it might come up on a couple practice exams and you just got to memorize it. But you don't need to know the mechanism or anything. If you have ketone, right? And you have NH3. I hate this mechanism so much. Because it's like, it's not even primed, and I refuse to believe that this happens like this, because the N's just not strong enough to get the oxygen to do that. I feel like you should have NH3, NH4+. And then get, like, the protonation. Like, that's what I think. But in the book, it's just written as NH3, so that's what I'm going to show you. Right? Proton transfer? How many steps? Two steps. Why isn't it one step? Because one, two, three, four, you don't make four-membered rings. All right, two steps. Proton transfer? O-H-N-H-2. All right? I also don't think that will happen, right? Okay. And then blah blah blah. And then obviously the OH picks that up and you get this guy which is known as what? This is an imine. This is an imine, very funny name. That's an imine. And I think that's an enamine. Immune-enamine. Let me make sure. Yeah, nitrogen on top of a double bond. Immune-enamine. And you can tautomerize between immunes and enamines. You can get a tautomerization, just like you can get keto-enol tautomerizations. Right? How do I think this reaction is going to happen in reality? Once again, don't copy this down. This is just for the sake of learning how organic reactions work. I think you put a little bit of H plus in here. Catalytic. And the H plus takes this and does that, and then that primes this to go like this. And then once you get this, you get that. And the solvent takes that away, and you get this, and then you get that, and then the H2O or the NH3, in order to remake the catalytic solvent, gets you... There. Quick orgo. Orgo on the fly. Okay. That's how you make an imine. And then that can tautomerize into an enamine. What is a tautomerization, my orgo people? Yeah, it's basically like resonance within a molecule when you put it inside of a base, right? So basically a keto enaltytomerism is when you have this and you can either have acid or base. Base is easier, obviously, right? Because you have this hanging H. And what's going to happen is that your base... What's that? What is that the first step of? What reaction? This is the first step of a very, very famous reaction, especially if I go like this. The Aldol reaction. Here's the first step of the Aldol reaction. From the base. Enol. Ketone. Ketone enol tetomerism. In the same sense, in the exact same sense, I mean, Ina mean. Except you need a stronger base. You probably need sodium amide. I mean, it means automerism. What's more stable, enols or ketones? Ketones. Very good. Why? Why? Huh? Well, let's look. I love this chapter. This chapter has layers. You're just peeling back layers of information. And it's only 8.36. Ketone. Enol What's the difference? Huh? Whenever I ask you about the stability of something with a double bond, it probably has to do with the p orbitals. So the p orbitals here are here and here. And p orbitals here are here and here. p orbitals are? Electronegative. And if you take something that's electronegative and get it to fight with something that's electronegative, they're not going to be happy. Because the p orbital pulls and then the oxygen pulls and the p orbital pulls and the oxygen pulls and the p orbital pulls and the oxygen pulls. Carbon just gives in. And the oxygen's like, hey, I got a p orbital and I'm electronegative, that's sick. That's awesome. It's quite unstable. Not, meh, meh, kind of. Which is why, which is why, oh my god, I love, I love this part. How do I do this again? I need to remember how to draw my structures. Yes. Yeah, yeah, yeah. What is that again? That is... It's oxidized. This is pyromate. What is this? Phosphoenolpyruvate. Phosphoenolpyruvate. Right? Because what is that? So let's get rid of the phospho. Right? For one second. For one second. Everyone follow me on the board. Put your pencils down. Everyone, down, down, down. That's pyruvate. What would enol pyruvate be? That ketone would turn into an enol. It can't turn into an enol this way because there's a carboxylate right there, right? It has to go to the right. If that turns into an enol, it's going to look like this. This is enol pyruvate. If we have phosphoenol pyruvate, That is phosphoenolpyruvate, or PEP, P-E-P, the last step in glycolysis before making pyruvate. So watch this. The formation of pyruvate from phosphoenolpyruvate makes what? makes ATP. And we said, when you make ATP, in order to synthesize that anhydride bond, you need a equal transfer of energy, right? And this is pyruvate kinase, right? Now, it makes sense, it kind of makes sense, right? That clipping this phosphate bond will give you energy, right? Because you're getting charge separation and you clip a bond and it creates energy, right? But that phosphate bond, it's not like connected to anything else special. We have to make what? We have to make... Oh, sorry. We have to make that. And that bond, this bond right here that we're making, is a lot higher energy than that bond, right? Because, look, there's a withdrawing group over there, and there's no withdrawing group. This is donating there, so it's a little more stabilized, right? So where do we get the rest of the energy from? Well, this is how the reaction happens. Ready? So first, the phosphate gets clipped. Phosphate gets clipped off, right? Minus PI. No PI over there, sorry. So first the phosphate gets clipped. And now you have a free PI that's in the enzyme next to the ADP waiting to get attached. What is that? It's an enol, right? And what is that? It's a ketone. And if the enzyme helps the enol pyruvate turn into keto pyruvate, since that's favorable and less energy, it releases enough energy to attach that phosphate onto the ADP. That's a coupled reaction. Isn't that fucking wild? Isn't that... You would never think... Like, no one would ever think... But you know who did? Professor Malitzky. Professor Malitzky did. He thought... Everything. Everything I know. Every single fucking thing I know about chemistry, that man taught me. And now I'm teaching you. And you'll teach someone else. And they'll teach someone else, and they'll teach someone else. And this is why when I die, I won't truly die. And neither will Professor Malitzky. He taught like an off-campus course that you like paid for. Very worth it. It was like $7.50 a semester for like 40 of his lectures. It was fantastic. Where is he right now? Florida. Yeah, he moved. Sorry, guys. You missed the boat. But yes, okay, so the addition, this phosphor anhydride bond is facilitated by A, the hydrolysis of a phosphate bond, and B, a favorable ketoenoltytomerism. That's a very common theme, coupled reactions. We'll talk about them a lot. Let's see if there's anything else to cover in the chapter. We did imines and enamines, right? Let's talk a little bit about carbohydrates. That's just when you have a cyanide that attacks and then connects. It's basically just a hydrate or a hemiacetal with cyanide. Oxidation of aldehydes forms carboxylic acids. Very good. And reduction of ketones is normally done with lithium aluminum hydride. Or an ABH4, right? Depending on how aggressive you want the reaction to be. One last thing, and we'll go home. Okay? It's another biochem connect. We stated that aldehydes... Let's use the green. You guys see the green properly? Better than the red or worse? Okay. We stated... Good, I don't like green anyways. We stated that aldehydes can react... What'd you say? Fuck off. It's like, okay, I have this conversation all the time because, like, I studied philosophy and this conversation I had with my philosophy professors and it's just like, how do you know, bro? How do you know? Are you asking me how I know? How do you know? How do you know you're not wrong? Huh? Prove it. Prove that's right. Prove it. What color is it? If I ask all of you what color this is, right? It's red, right? Even I would say it's red. But here's the philosophical problem. So two dudes are having a little chit-chat, right? And they're looking at a tree. Like, oh, look, great tree. And the other dude's like, oh, yeah, awesome tree, dude. Great leaves, great bark. Look at that squirrel. Fantastic. Another dude comes around and he's like, oh, that's a fucked up looking dog. Right? And the dude walks away. And the two dudes are like, what the fuck is that guy on about, right? Is he? Can you prove him wrong? Can you prove him wrong? No, because what I want you to think about when you go home tonight is that our preconceived notion of perceptual reality is rooted not in fact, but in linguistics. There are no facts in the world around you. It is purely rooted in a collective unconscious that buys into the principle that this is called red. There's no factual information about this being called red. So it doesn't matter what I call it, I see it how I see it, and you see it how you see it, and neither of us can prove each other correct. And we never will be able to. And that's why I'm not wrong. Okay, anyways, aldehydes, right? So go think about that when you're home tonight, that there exists no factual information in the world around you. None. Everything's made up. Aldehydes. So we said that aldehydes can react with ROH. In order to make what? In order to make acetyls and hemiacetyls, right? Hmm. But what if the ROH is the aldehyde? What if, what if, right? What if we had a little guy, a little silly little guy, right? Who looked like this. 1, 2, 3, 4, 5, 6. Aldehyde and ROH. Interesting, right? So what if we have... Oh, sorry, sorry, sorry, sorry, sorry, sorry. I was already thinking ahead. So aldehyde and ROH. And we take this funny little guy, and we put him in a solution of acid. So what happens is... Every-pens down. No, no writing this. None. Because we're gonna write it so many times in the future. And you'll see why. So that guy... 1, 2, 3, 4, 5, 6-membered ring. This guy's gonna fucking jump off a cliff. Alright, 6-membered ring. All right, follow me here. 1, 2, 3, 4, 5, 6. All right, so 1, 2, 3, 4, 5, 6, right? On carbon 2, this is number 1. On carbon 2, we have a methyl group. Carbon 3, 4, 5, 6. 6, we have this OH and a hydrogen. The hydrogen can go bye-bye, and this has a hydrogen on it. And that will get deprotonated, and you will make... So what's the hemiacetal here? It's this. This carbon has an OH and an OR. It's just in the same molecule. You guys ready for me to blow your fucking mind again? Does anyone know where this is going? You know where it's going. Yep. Glucose, in its straight-chain form, is able to get protonated and attacked and form a hemiacetal, where the closed-chain form of glucose, the ring form of glucose, which looks like this, will draw beta-D-glucose. And there you go. O-R-O-H. That is a hemiacetal. That is a hemiacetal. And sometimes, when other sugars come along and attach there, you can get full-blown acetals. So glucose is a hemiacetal, and specifically, it's this OH right here. One, two, three, four, oh, sorry, not that OH. This OH, the penultimate OH, as Professor Malitzky would say. Penultimate meaning one before the last. One, two, three, four, five, six-membered ring. Yeah, yeah, yeah. Glucose is your middle finger. So the thumb is the aldehyde, right? And you put the middle finger up and you put it against the board. Your fingertips are the OHs. And your wrist is the last OH right there. Like that. So if you ever want to draw glucose, flip off the page, draw in your OHs. With your right hand. So, glucose is a hemiacetal, right? Which means that it can go forward and go back and go forward and go back, and it does that about a million times a second. I'm serious. That's what Professor Mlodzki told me, that that happens a million times a second. And I believe him. I believe, I would, he could tell me 2 plus 2 is 5 and I believe him. It doesn't matter if 2 plus 2 is 5 because nothing's real anyways. I took a metaphysics course in my senior year for my philosophy major. And if you guys have an extra course lying around for your seniors, it is quite difficult. It's hard to get an A in, so I wouldn't recommend taking it if you care about your grade. But if you ever get in... interested in philosophy and just want to talk to some philosophy professor, talk to Professor Sam Trivedi. He's fantastic. He teaches the metaphysics course here, and it's super complicated. We had so many discussions about what's zero, what are abstract concepts, what are colors, what is emptiness, what is nothing if there's... there's still air in there. What is a hole? Is a hole the opening of the hole or is it the thing within the hole or is it the air in the hole? Like, it's crazy. It's like the study of ontology, which is the nature of reality. It's beautiful, beautiful course. Anyways, that being said, now that I've literally given you a biochem lecture instead of Orgo, thank you guys so much for listening. It's 8.51. Had a great time. I'm really happy I got to give this lecture. And next time we will talk about eating the hole. enolates, and anions, which is very, very important because we get to talk about the aldol reaction, the Claisen reaction, and all that stuff. Then we'll talk about carboxylic acids. That goes super quick. Carboxylic acid derivatives we pretty much did, but we'll glaze over them once again. And then after that, it's all stuff that I don't teach you. So it's nitrogen-containing compounds, which is literally just like 15 minutes of a lecture. And then it's spectroscopy, which I'll send you videos for. And then we will save lab techniques. There's a chapter on lab techniques. We will save it for when we're in the practice phase. going to fucking forget. You're going to forget. And lab techniques deserve their own dedicated time. Let's do questions. Let's talk about the lab techniques. Let's talk about how they work, blah, blah, blah, blah, blah. Thank you guys so much for listening. Thank you for watching back home. Thank you for keeping up. And I'm very happy to be back. I'll see you guys next time.

Welcome back. Chapter 6 is aldehydes and ketones, which are formed by the oxidation of... alcohols, which are formed by the oxidation of general compounds, right?

So in organic chemistry, if you take a basic hydrocarbon structure and you oxidize it, you can turn it into an alcohol, and then turn it into an aldehyde or a ketone. You might turn it into an acid, and you might even turn it into carbon dioxide, right? You're going up the oxidation ladder.

And that's the way they actually structure these chapters as well. They go up the oxidation ladder. It's just that no one ever told you that. And now I'm holding your hand through it, right? So we talked a little bit about...

So naming different ketones and aldehydes, stuff like that. When it's not the highest priority, it's oxo. When it is the highest priority on a ketone, it's one, O-N-E, like butanone. And then in aldehyde, it's butan-al, right? Cool.

So the first thing is nucleophilic addition reactions to ketones and aldehydes. So... I'm going to talk to you about hydrate formation.

So if we have an aldehyde, acid aldehyde, and we put it in a solution of acidified water, we can observe a protonation of the carbonyl oxygen That will swiftly be followed by attack of the labile carbonyl carbon. And in order for the... Sorry.

In order for the reaction to propagate, it is more than likely, or just for the simplicity of the reaction, we write that this gets deprotonated by another one of these starting material in order to perform the first step of the next reaction. Right? So we see the carbonyl carbon coming, grabbing that, and we get, when in reality, it's probably the solvent that's coming in to do this.

And it's going to make another H3O+, and then that's going to protonate another thing like this, blah, blah, blah, right? And then we get something known as a hydrate. I will quite literally, let me make sure I'm naming this properly. I am. I will give five dollars to anyone who can tell me what type of molecule that is, other than a hydrate.

What type of dial? There's two types of dials. This is a specific one.

I can't give you any more hints than that. That's coming next. That's reducing sugars.

We'll talk about that in a second as well. This is called a geminal dial. A geminal dial. Which is different than a vicinal dial. A vicinal dial looks like this.

And it's what you create when you react a double bond with OSO4. A vicinal dial. That is a vicinal dial. How do you remember geminal and vicinal?

I always thought that this little two-spoke thing and the circles look like a gem, like little diamonds on top of spokes. Geminal and vicinal means they're just in the same vicinity of one another. They're not on top of one another. They're just in the same neighborhood, right? Geminal and vicinal dials.

Like the pinnacle rearrangement begins with a vicinal diol. So a vicinal diol, otherwise known as a hydrate. And this is an aldehyde hydrate because there's an H right there.

To make a ketone hydrate, the same exact thing. If you don't wish to copy this down, you don't have to because it's literally the same thing that we just did. I'm doing it for the sake of completion.

Geminal dial from a ketone because there's no H over there. Good? I'll give you a second.

I get tired up here sometimes. We should throw a party our last day here. No, like when I leave you guys on your own and you never see me again ever.

Oh my god, no. Huh? You can finally clap on that day, yeah.

Oh no, I'm coming back next year. And the next year, and the year after that. Yeah, I'll see you guys all the time, don't worry.

I mean, I'll see you guys. I might see a couple of you guys at medical school. Who knows?

I'm sure a couple of you will come to Downstate. Here's hoping. What's the Downstate MCAT average for my class? 5.16.

5.16. We have nine people who scored above a 5.20, and I'm one of them. In a class of 230, I think.

But, Downstate loves to take kids from Brooklyn. So, roll your dice and do well. Both.

Roll your dice, do well, stay consistent, and focus when I'm teaching. We talked about... hydrates and you brought up a very good term.

What did you talk about in a second go? Hemiacetals and acetals. So it's basically the same thing. And the acet, like the al ending, right?

Al means we're working with aldehydes mainly. This mostly happens with aldehydes. So hemiacetal slash acetal. Hemiacetal, acetal, right? So this is when we, instead of water, we use alcohol.

So we get protonation. Protonation of the carbonyl oxygen by the protonated solvent, correct? We have a reversible process which creates this.

We will get ROH, now a good nucleophile because this is primed for attack, to attack there. And we get O, R, H, and OH. And deprotonation of this by the solvent yields... H-O-R-O-H. O-R and O-H on the same carbon means what?

Means acetal. Sorry, sorry, hemiacetal. It's half. Hemiacetal. Half an acetal.

Hemiacetal. Half. Half of what?

Well the OR is what makes it an acetal. So it's half of that. If both of them were OR it would be an acetal. One of them is an OR, it's a hemiacetal. So how do we make a full-blown acetal?

We take that and we keep reacting it. And now this is where people start to get lost. Because it doesn't look like that's going to keep reacting.

But it will. Because... You have this, O-R-O-H, and instead of protonating the O-R and going backwards, why don't we protonate the O-H and see what happens?

So, R-O-H2 plus will protonate the O-H and make another molecule of R-O-H on the side along with O- R and O H2. And now that that's a good leaving group, instead of making the carbocation, let's do a very famous biochem move, very famous upper-level orgo biochem move called assisted leaving. Not assisted living.

Assisted leaving. Where the electrons here kind of give this guy the boot. Hey, fuck off.

Get out of here. You're already a good leaving group. Get out of here.

Right? So that guy gives that guy the boot, right? And we get... Wow.

That, that's impressive. Why is that impressive? Because now, look back to the first reaction.

We basically have the beginning step of the last reaction, but with an R instead of an H. That's incredible. That's really cool. That the solvent completely...

Completely changed the way this is. Because normally, you can't get an R to attach to a carbonyl carbon like that. You can't.

It's just not going to happen. Right? Unless the R was positive and somehow it got attacked and something like that.

Plus, that's not, like, when you have this. Sorry, I forgot my H. When you have this, and if you had this, that's not even, like, negative enough to attack there. So it's so hard to do that, but now we just did.

Right? We just did. And now you might be thinking, you know, well, we kicked off this water. Wouldn't the water just attack back right here? Isn't that what we've been seeing all this time?

But you have to think. You have to think. When we do a reaction like this, the water came from where?

It came from the beginning when we were working with this guy. The water is that. It's this oxygen that got protonated twice by the alcohol, right?

So both those hydra... This is where your knowledge of... Atom tracking needs to come in.

That water is, that oxygen is one of these original oxygens that got kicked off, and both those hydrogens came from the solvent. Right? You need to be cerebral enough to see that.

And if you're not, it'll come with practice, I promise. Right? So why wouldn't the water just come back here? Well, we know that this water, that oxygen, came from the solvent.

So, sorry, it came from the reactant. What do we have more of, solvent or reactant? The solvent is always in like 10,000, 100,000, 1 million time excess, right?

So if we have one of these, we have a million of these. So which one's more likely to attack? The ROH.

Fine. Done, right? H-O-R from there and O-R-H from the solvent. And now R-O-H solvent will deprotonate. Why does solvent deprotonate?

Because there's so much more of it than everything else. And we get H-O-R-O-R. That is a full-blown acetal. Everyone clap for the acetal.

Yeah, you made it. He's so cute. I love him.

When it's with aldehydes, it's called acetal. When it's with ketones, it's called a ketal. Hemiketals and ketals.

I'm not going to draw out the whole thing again. Replace the H with a CH3. Happens a lot more with aldehydes, though.

They're more electrophilic than ketones are. Why? To further solidify our conversation, right?

It has nothing to do with the SP2 character of whatever's going on, right? We know that these are both withdrawing groups, slightly negative and slightly positive, right? Slightly negative, slightly positive, slightly positive, right? Why is this more electrophilic than that? It has to do with the CH3 group on it, right?

The H versus the CH3. Remember what I told you about R groups? R groups are donating.

They donate some electron density onto there, so it decreases the electrophilicity of that carbon. Does that make sense? Good.

You can explain everything. You can explain all of it. I promise you, you can explain all of it with very, very basic chemistry. If you remember a couple basic rules. Ummm...

I like don't really like this one that much but we should talk about it because it'll come up every now and again just in nomenclature. Everyone put your pencils down. I do not want you to copy this.

Just look. Look at it once. It's going to come up in your Anki.

And it might come up on a couple practice exams and you just got to memorize it. But you don't need to know the mechanism or anything. If you have ketone, right? And you have NH3.

I hate this mechanism so much. Because it's like, it's not even primed, and I refuse to believe that this happens like this, because the N's just not strong enough to get the oxygen to do that. I feel like you should have NH3, NH4+. And then get, like, the protonation.

Like, that's what I think. But in the book, it's just written as NH3, so that's what I'm going to show you. Right? Proton transfer?

How many steps? Two steps. Why isn't it one step?

Because one, two, three, four, you don't make four-membered rings. All right, two steps. Proton transfer? O-H-N-H-2. All right?

I also don't think that will happen, right? Okay. And then blah blah blah.

And then obviously the OH picks that up and you get this guy which is known as what? This is an imine. This is an imine, very funny name. That's an imine.

And I think that's an enamine. Immune-enamine. Let me make sure.

Yeah, nitrogen on top of a double bond. Immune-enamine. And you can tautomerize between immunes and enamines.

You can get a tautomerization, just like you can get keto-enol tautomerizations. Right? How do I think this reaction is going to happen in reality? Once again, don't copy this down.

This is just for the sake of learning how organic reactions work. I think you put a little bit of H plus in here. Catalytic. And the H plus takes this and does that, and then that primes this to go like this. And then once you get this, you get that.

And the solvent takes that away, and you get this, and then you get that, and then the H2O or the NH3, in order to remake the catalytic solvent, gets you... There. Quick orgo. Orgo on the fly. Okay.

That's how you make an imine. And then that can tautomerize into an enamine. What is a tautomerization, my orgo people? Yeah, it's basically like resonance within a molecule when you put it inside of a base, right?

So basically a keto enaltytomerism is when you have this and you can either have acid or base. Base is easier, obviously, right? Because you have this hanging H.

And what's going to happen is that your base... What's that? What is that the first step of?

What reaction? This is the first step of a very, very famous reaction, especially if I go like this. The Aldol reaction.

Here's the first step of the Aldol reaction. From the base. Enol.

Ketone. Ketone enol tetomerism. In the same sense, in the exact same sense, I mean, Ina mean.

Except you need a stronger base. You probably need sodium amide. I mean, it means automerism.

What's more stable, enols or ketones? Ketones. Very good. Why? Why?

Huh? Well, let's look. I love this chapter.

This chapter has layers. You're just peeling back layers of information. And it's only 8.36. Ketone.

Enol What's the difference? Huh? Whenever I ask you about the stability of something with a double bond, it probably has to do with the p orbitals.

So the p orbitals here are here and here. And p orbitals here are here and here. p orbitals are? Electronegative. And if you take something that's electronegative and get it to fight with something that's electronegative, they're not going to be happy.

Because the p orbital pulls and then the oxygen pulls and the p orbital pulls and the oxygen pulls and the p orbital pulls and the oxygen pulls. Carbon just gives in. And the oxygen's like, hey, I got a p orbital and I'm electronegative, that's sick.

That's awesome. It's quite unstable. Not, meh, meh, kind of. Which is why, which is why, oh my god, I love, I love this part. How do I do this again?

I need to remember how to draw my structures. Yes. Yeah, yeah, yeah. What is that again?

That is... It's oxidized. This is pyromate. What is this? Phosphoenolpyruvate.

Phosphoenolpyruvate. Right? Because what is that?

So let's get rid of the phospho. Right? For one second.

For one second. Everyone follow me on the board. Put your pencils down.

Everyone, down, down, down. That's pyruvate. What would enol pyruvate be? That ketone would turn into an enol.

It can't turn into an enol this way because there's a carboxylate right there, right? It has to go to the right. If that turns into an enol, it's going to look like this. This is enol pyruvate. If we have phosphoenol pyruvate, That is phosphoenolpyruvate, or PEP, P-E-P, the last step in glycolysis before making pyruvate.

So watch this. The formation of pyruvate from phosphoenolpyruvate makes what? makes ATP. And we said, when you make ATP, in order to synthesize that anhydride bond, you need a equal transfer of energy, right? And this is pyruvate kinase, right?

Now, it makes sense, it kind of makes sense, right? That clipping this phosphate bond will give you energy, right? Because you're getting charge separation and you clip a bond and it creates energy, right?

But that phosphate bond, it's not like connected to anything else special. We have to make what? We have to make...

Oh, sorry. We have to make that. And that bond, this bond right here that we're making, is a lot higher energy than that bond, right?

Because, look, there's a withdrawing group over there, and there's no withdrawing group. This is donating there, so it's a little more stabilized, right? So where do we get the rest of the energy from?

Well, this is how the reaction happens. Ready? So first, the phosphate gets clipped. Phosphate gets clipped off, right?

Minus PI. No PI over there, sorry. So first the phosphate gets clipped.

And now you have a free PI that's in the enzyme next to the ADP waiting to get attached. What is that? It's an enol, right?

And what is that? It's a ketone. And if the enzyme helps the enol pyruvate turn into keto pyruvate, since that's favorable and less energy, it releases enough energy to attach that phosphate onto the ADP.

That's a coupled reaction. Isn't that fucking wild? Isn't that... You would never think... Like, no one would ever think...

But you know who did? Professor Malitzky. Professor Malitzky did. He thought... Everything.

Everything I know. Every single fucking thing I know about chemistry, that man taught me. And now I'm teaching you.

And you'll teach someone else. And they'll teach someone else, and they'll teach someone else. And this is why when I die, I won't truly die.

And neither will Professor Malitzky. He taught like an off-campus course that you like paid for. Very worth it. It was like $7.50 a semester for like 40 of his lectures.

It was fantastic. Where is he right now? Florida.

Yeah, he moved. Sorry, guys. You missed the boat.

But yes, okay, so the addition, this phosphor anhydride bond is facilitated by A, the hydrolysis of a phosphate bond, and B, a favorable ketoenoltytomerism. That's a very common theme, coupled reactions. We'll talk about them a lot. Let's see if there's anything else to cover in the chapter. We did imines and enamines, right?

Let's talk a little bit about carbohydrates. That's just when you have a cyanide that attacks and then connects. It's basically just a hydrate or a hemiacetal with cyanide.

Oxidation of aldehydes forms carboxylic acids. Very good. And reduction of ketones is normally done with lithium aluminum hydride. Or an ABH4, right?

Depending on how aggressive you want the reaction to be. One last thing, and we'll go home. Okay?

It's another biochem connect. We stated that aldehydes... Let's use the green.

You guys see the green properly? Better than the red or worse? Okay.

We stated... Good, I don't like green anyways. We stated that aldehydes can react...

What'd you say? Fuck off. It's like, okay, I have this conversation all the time because, like, I studied philosophy and this conversation I had with my philosophy professors and it's just like, how do you know, bro? How do you know?

Are you asking me how I know? How do you know? How do you know you're not wrong? Huh?

Prove it. Prove that's right. Prove it. What color is it?

If I ask all of you what color this is, right? It's red, right? Even I would say it's red. But here's the philosophical problem.

So two dudes are having a little chit-chat, right? And they're looking at a tree. Like, oh, look, great tree.

And the other dude's like, oh, yeah, awesome tree, dude. Great leaves, great bark. Look at that squirrel.

Fantastic. Another dude comes around and he's like, oh, that's a fucked up looking dog. Right?

And the dude walks away. And the two dudes are like, what the fuck is that guy on about, right? Is he? Can you prove him wrong?

Can you prove him wrong? No, because what I want you to think about when you go home tonight is that our preconceived notion of perceptual reality is rooted not in fact, but in linguistics. There are no facts in the world around you.

It is purely rooted in a collective unconscious that buys into the principle that this is called red. There's no factual information about this being called red. So it doesn't matter what I call it, I see it how I see it, and you see it how you see it, and neither of us can prove each other correct.

And we never will be able to. And that's why I'm not wrong. Okay, anyways, aldehydes, right? So go think about that when you're home tonight, that there exists no factual information in the world around you. None.

Everything's made up. Aldehydes. So we said that aldehydes can react with ROH.

In order to make what? In order to make acetyls and hemiacetyls, right? Hmm. But what if the ROH is the aldehyde?

What if, what if, right? What if we had a little guy, a little silly little guy, right? Who looked like this.

1, 2, 3, 4, 5, 6. Aldehyde and ROH. Interesting, right? So what if we have... Oh, sorry, sorry, sorry, sorry, sorry, sorry. I was already thinking ahead.

So aldehyde and ROH. And we take this funny little guy, and we put him in a solution of acid. So what happens is... Every-pens down.

No, no writing this. None. Because we're gonna write it so many times in the future. And you'll see why.

So that guy... 1, 2, 3, 4, 5, 6-membered ring. This guy's gonna fucking jump off a cliff.

Alright, 6-membered ring. All right, follow me here. 1, 2, 3, 4, 5, 6. All right, so 1, 2, 3, 4, 5, 6, right?

On carbon 2, this is number 1. On carbon 2, we have a methyl group. Carbon 3, 4, 5, 6. 6, we have this OH and a hydrogen. The hydrogen can go bye-bye, and this has a hydrogen on it.

And that will get deprotonated, and you will make... So what's the hemiacetal here? It's this.

This carbon has an OH and an OR. It's just in the same molecule. You guys ready for me to blow your fucking mind again?

Does anyone know where this is going? You know where it's going. Yep. Glucose, in its straight-chain form, is able to get protonated and attacked and form a hemiacetal, where the closed-chain form of glucose, the ring form of glucose, which looks like this, will draw beta-D-glucose.

And there you go. O-R-O-H. That is a hemiacetal. That is a hemiacetal. And sometimes, when other sugars come along and attach there, you can get full-blown acetals.

So glucose is a hemiacetal, and specifically, it's this OH right here. One, two, three, four, oh, sorry, not that OH. This OH, the penultimate OH, as Professor Malitzky would say. Penultimate meaning one before the last. One, two, three, four, five, six-membered ring.

Yeah, yeah, yeah. Glucose is your middle finger. So the thumb is the aldehyde, right? And you put the middle finger up and you put it against the board. Your fingertips are the OHs.

And your wrist is the last OH right there. Like that. So if you ever want to draw glucose, flip off the page, draw in your OHs.

With your right hand. So, glucose is a hemiacetal, right? Which means that it can go forward and go back and go forward and go back, and it does that about a million times a second. I'm serious.

That's what Professor Mlodzki told me, that that happens a million times a second. And I believe him. I believe, I would, he could tell me 2 plus 2 is 5 and I believe him. It doesn't matter if 2 plus 2 is 5 because nothing's real anyways.

I took a metaphysics course in my senior year for my philosophy major. And if you guys have an extra course lying around for your seniors, it is quite difficult. It's hard to get an A in, so I wouldn't recommend taking it if you care about your grade.

But if you ever get in... interested in philosophy and just want to talk to some philosophy professor, talk to Professor Sam Trivedi. He's fantastic.

He teaches the metaphysics course here, and it's super complicated. We had so many discussions about what's zero, what are abstract concepts, what are colors, what is emptiness, what is nothing if there's... there's still air in there. What is a hole? Is a hole the opening of the hole or is it the thing within the hole or is it the air in the hole?

Like, it's crazy. It's like the study of ontology, which is the nature of reality. It's beautiful, beautiful course.

Anyways, that being said, now that I've literally given you a biochem lecture instead of Orgo, thank you guys so much for listening. It's 8.51. Had a great time.

I'm really happy I got to give this lecture. And next time we will talk about eating the hole. enolates, and anions, which is very, very important because we get to talk about the aldol reaction, the Claisen reaction, and all that stuff. Then we'll talk about carboxylic acids.

That goes super quick. Carboxylic acid derivatives we pretty much did, but we'll glaze over them once again. And then after that, it's all stuff that I don't teach you. So it's nitrogen-containing compounds, which is literally just like 15 minutes of a lecture. And then it's spectroscopy, which I'll send you videos for.

And then we will save lab techniques. There's a chapter on lab techniques. We will save it for when we're in the practice phase.

going to fucking forget. You're going to forget. And lab techniques deserve their own dedicated time. Let's do questions.

Let's talk about the lab techniques. Let's talk about how they work, blah, blah, blah, blah, blah. Thank you guys so much for listening. Thank you for watching back home.

Thank you for keeping up. And I'm very happy to be back. I'll see you guys next time.

Transcript for:Understanding Aldehydes and Ketones

Transcript for:
Understanding Aldehydes and Ketones