Monosaccharides - Kiliani-Fischer

Hey, guys, in this video, I'm going to show you guys how to make mono sack ride chains longer through a process called the kill Janni Fisher synthesis. Alright, guys. So you have to love sack rides because Sacha rides have alcohols, they have carbon eels. There's so many different things we could do with them. So they're so versatile. And one thing that you should always keep in mind is that the reactions that we learned about Alba hides and key tones back in your carbon Neil section of organic chemistry apply. Many of those reactions apply to sack rides because we have an alga hide present. Okay, so just keep in mind that many of the same nuclear feel like addition reactions that we learned in your carbon Neil chemistry chapter are going to apply to that. Aldo hide. Okay, now, specifically, when we expose an alga hide to H c n hydrogen cyanide, all doses can reverse a ble transform into Cyan. Oh, hydrants. Ok, now, guys, this shouldn't be a shock to you because this is exactly what we learned back when he did Carbonell chemistry. Okay, What we learned is that if you react in Aldo Hide or a key tone with H c n. What's gonna end up happening is that you get a CNN negative that comes in and attacks and kicks electrons up to the O right. So we're just drawing out the Sino hydro mechanism right now. And then what would happen? This is called a nuclear Filic edition. The sand would attack the positive of the carbon. He'll kick the elections up to the Uh Oh. What you would get now is a C triple bond n attached to that carbon carbon. And then you would get a C a no minus and that all minus would later on get protein ated by this h that disassociated. So eventually this becomes an O. H. And guys, this is what we call a scion a hydrant functional group. Okay, so everything that I just showed you is 100% based on other videos. If you want to type in Sion a hydrogen to your search bar right now, you will find the same exact mechanism just instead of working with sugars, we were just working with a regular al die. Okay, so there's zero new information here Now what's interesting is that we can take advantage of the fact that scion oh, groups have an extra carbon. We can take advantage of that fact toe length in the chain. And if we can keep adding scion oh, groups, we can keep leg lengthening this chain. So ideally, we could turn ah, pen toes into ah heck sauce by just adding more and more Santa hydrants. Okay, Now, the way that we do this is that we're gonna have Thio hide relies that CNN and turn it into a car. Uh, turn into a carbon deal in some way. Okay, so let's go ahead and figure out how to do that. Okay, So it says the Sino group can then be reduced and hydrolyzed to form a new chain length and alga hide. Okay. So, guys, it turns out that we have learned in the past how to reduce night trials or Cyan oh, groups. Okay, But when we have studied reduction of Santa groups in the past, it's usually been with catalytic hydrogenation. And what catalytic hydrogenation does is it adds, hydrogen is toe every pi bon. So if we just used, for example, h two and palladium, let's say if we just use that as catalytic hydrogenation, What we would expect to get is ch two. Don't draw this, by the way, because this is the wrong answer. And h two okay, it would completely reduce. We would add a ton of H is now. It turns out that we don't want this because we only want to reduce it to a double bond, not to a single bond, because we want to keep a carbon meal. Okay, so what we're gonna do is we're gonna We're going to develop some kind of reduction, not this one, but we're going to develop some kind of reduction, some weak or form of reduction toe. Leave it as an N as a c N double bond. So we're gonna do this. See, Double Bond and H. And then obviously this H is still present. Now, you don't know what this reducing agent is, but I'm just letting you know that that's gonna be part of the synthesis is defined. The reducing agent that Onley reduces it. One step and not two steps. Cool. Then, once you have this functional group, this is called an Emmy. And guys, we learned back in the carbon you'll in the Carbondale chapter that it means can be reversible e hydrolyzed into carbon eels using just water and acid through hydraulic sis, it's possible to turn that end into an O. Okay, Now, if you're wondering, Johnny, this is just going over my head. I don't know any of these reactions. I have all these on video, So if you type in a mean and you'll see all the immune reactions and you'll see mechanisms of how we can turn a dull bon end into a dull bon Oh, if you search Sino hydrants, you can look at the first step. So, really, the steps that you should already know from what we've already learned in organic chemistry are this step and this step. Both of these steps come from carbon chemistry, the Onley step. That should still be a big question mark for you Is this step and that's fine, because I'm gonna explain that step Maurin a little bit. Okay, cool. So just before I go into the specific re agents into the specific mechanisms, I'm trying to give you the big picture and one thing I want to show you. Oh, by the way. I'm sorry, this would still be in age, but one thing I want to show you is that this synthesis can be repeated multiple times because notice that at the end we end up with an alga hide that is now one carbon longer than before. Right before I started with ribose, which is a pen toes. Right now I have 123456 carbons and I still have an alto high present. What canal the hides do when you expose them toe to see a negative, they can react again and they could do another sign, a hydrant. So the whole idea here is that you can repeat this cycle as many times as you want and get your carbon chain to be longer and longer and longer, and you could theoretically just keep on going forever. Okay, now, one thing to keep in mind in mind, though, is that the Cairo ality at carbon too is always going to be a mixture. It's never gonna be a solid, um Dia stereo murderer, solid configuration. And the reason guys is because this carbon here is the same as this carbon here. It never had chi rally. It started off as a Cairo because it was tribunal plainer. And now, after we've added the alcohol, we don't know which side the alcohol added to it could have added from the right. It could have added from the left. So the one limitation of Colleoni Fisher is even though it's a great way to lengthen the chain, you're going to continue to get mixtures of configurations at every carbon as you go up. The more times you do it, the more uncertain carbons you're gonna have, where you don't know if the O H faces towards the right or if the O. H faces towards the left. What you're actually gonna get is a mixture of both. And actually it's not even 50 50 because these air dia steri um er so they tend to have different properties, so it could be a mess. It could be like 60% of the right and 40% of the left, like you don't really know. So that's just one of the limitations of Kilian Fisher. Does that make sense? So far? Cool. So in the next video, what I want to do is I want to talk about some specific re agents, and I want to talk about why, why in my title it's modern, Colleoni Fisher on. I'll explain that in the next video.

So why did I call this reaction? The modern kill Janni Fisher synthesis? Well, guys, that's because when doctors kill Janni and Fisher first made this reaction, they were using slightly different re agents. So the first step was the same. It was still done through a scion. Oh, hydrogen. So what they would do is just as I explained in the first step on the previous video, they would add a C N group here and this would become an O. H. And they would form a sign a hydrant. So that part was identical. But the re agents that they used afterwards to hide relies that CNN were actually very different. It required mawr steps, so it required to additional steps, and it resulted in poor yields. OK, so it was a very important reaction at the time back in the 18 hundreds, but we've had 150 years to improve it. And now the new set of re agents is what would be referred to as the modern Kelly Anne Fisher. Okay, quote. So what are these newer re agents? So, guys, it turns out that we were able to design a better reducing agent that would work on the CNN and turn it into an Emmy. Okay, And this reducing agent, you've never really seen this exact reducing agent before. But it's similar to other ones that we've seen because what it is is it's hte too comma palladium. So this looks like catalytic hydrogenation, But it's not exactly palladium. It's palladium on Vary, um, sulfate. So PD over B A s 04 this combination, you're just enough to memorize it. Probably put it in a flash card. This is what we call a poisoned reducing agent. And why What poison means? Guys, if you ever hear the term poisoned, it means weaker. Okay, so whenever you hear of poison, that means it's weaker than normal. Normal. So another term of a poison. Another poisoned hydrogenation is Lynn Lars Catalyst. Remember Howlin Lars? Instead of going from triple bond to single bond, it goes toe assist double bond. This goes all the way to organic chemistry one. Well, in the similar way, this is a poisoned catalysts because instead of I'm turning my C n into CH to an N H. Two, which is what we would expect from a regular catalytic hydrogenation what it's going to turn it into is remember that this is a triple bond, right? So I'm gonna just write it again in the Triple One. It's going to turn it into C double bond N h. And then this is a ch okay, And once again, let's just go ahead and write the re agents in. It's going to be hte too palladium and bear him selfie cool. And once again, this is important because it turns it into an Emmy. And once we have that, I mean we can use Imean. Hydraulics is which is a reaction that we learned a long time ago in Carbondale chemistry to turn this into a carbon, Neil. So then it will look like this. It's gonna go back to being an alga high, and as we know, this age is still there. So we're just going to get a an alcohol there. And as we already talked about this is the reason this is squiggly is because it's going to be a mixture of die hysteria murders, because we don't know exactly where that o. H is going to attach from. Okay, So, guys, what you need to know is that the modern Kilani Fisher uses this palladium and barium sulfate, and you should probably know each intermediate step how you're reducing tau IMing. And then how on IMing is being hydrolyzed in an aqueous solution? Back to the alto hide. Cool, awesome guys. So we're done with this video. Let's move on to the next.