Merken

Lecture 15. Reduction and Oxidation, Part 3

Zitierlink des Filmsegments
Embed Code

Automatisierte Medienanalyse

Beta
Erkannte Entitäten
Sprachtranskript
Back to another episode of what's going on in the world and the world of work it's just in the world of chemistry Sun news article that had something to do with the drugs that can help people lose weight to control their weight and for that this headed in the study were some investigators at the University of Michigan started screening drugs there were already approved in democracy might do something of the city you as we have heard of this thing called the fen-phen diet pills the 1990 is 1 of many different types of drugs where people have high hopes that it could help people lose weight and keep weight off most of those kinds of drugs over work hours because of problems are so they're still waiting to see if this particular compound that they found which seems to be very effective will have those problems in humans as well of course but they showed is that this oral medication which is actually used to treat caters to workers in the mouse on it turns out that when the injecting animals with the drug and Lexa knocks on the big difference in the way it so that I can eat whatever the fact that had wanted and ended up I'm all for that and get out of here some that I can take so that I can eat whatever I want on so they wouldn't talk about this Lexa knots I never heard events but before it's not a it's not a billion dollar pharmaceutical that something has clearly been on the market for a long
time is the structure of election Knox appear and you could see it's a sandstone colonies as a encompasses a nitrogen in the rain and the target of this is this coming needs here called tanks 1 kind means he became 1 and there's another kind he's here they're not quite clear as to what the mechanism is this was supposed to be an epsilon according just call this this signal transduction diagram of where there's still tremendous sort out this pathway on weekend nights an ox is believed to act and the problem is with the 3 years that picture is generated by my cell biologist at an aggregate of many different types of human cells and so that means it's not perfectly accurate and so the key point here is that if you look like a silver gets infected by a virus there's something called the toll like receptor that sends messages inside cell and that message is controlled to some extent by these 2 protein kindnesses that kind such that that fast for related transcription factor which then turns on genes and the effect of those genes depends on what type of sellers it's an immune system cells begin to non-interference that help fight violent factions other types of cells that simply reflected a concern that message for genes that basically states that don't die but the pumping out new virus and you really like a drug that inhibits that you'd like those altered on the infected by the virus as while as those same kinds of pathways it turns out controller did the sites you would like .period decides not to proliferate traffic like them just stay quiet hasn't stopped live proliferating stopped growing on its drug seems to have the same effect and let's not that significant is that the virus infected cells and the school so hopefully again I'm not holding out high hopes but the general trend is usually when they find things that this on induce weight loss but usually those things over works of art and have other problems associated with them but I'm sure hoping for that organic chemistry to come to my rescue so we're going to finish up let's go back to the chemistry at hand today for Chapter 12 in the Gordon's Eastern time and we
just finished talking about diet hydroxyl aging mediation to hydroxyl groups across a double bond and we talked about 2 different ways that you could do that 1 wagered epoxy a double bond and then Hydro lies the apart said opens beginning in the disposition of hydroxyl word the other way that duties using wasn't intent side and animal this secret Cowie collegiate oxygen and then adds 2 hydroxyl groups on the same side of the double bonds and so you need to distinguish those 2 patterns 2 hydroxyl groups and end up on opposite sides or whether the 2 hydroxyl group to end up on the same side so that all the talk about a complete different type of reaction about teens and 1 that this is the kind of money reaction you'll be using for the rest of the camp 51 series on through constituency that they'll be strongest reaction to it and it's called always analysis it's reactionaries ozone just like the ozone in the stratosphere that absorbs ultraviolet light a weird little electrical ozone generators evil oxygen gas through a current through a high-voltage current and converts the oxygen gas and 0 euros so you don't really need to know the structure of ozone hole good draw residents structures this rebalanced oxygen you have to have a positive charge 1 bond oxygen estimated shortage so that's the structure of ozone but what we're interested in years the reactions of ozone so let me give you a couple of examples of of what you can do with ozone and that the phrase here is cleavage you clean Dublin hands with ozone and it is always a 2 step sequence the way you those so there's ozone O 3 that's all you have to write 0 3 is a gas so again in the latter this machine generate ozone gas public into a solution you can either public directly into your reaction solution of free make a dilute solution of the ozone in songs like methanol soul when we carry out this this cleavage reaction and you don't follow it with a 2nd step that is always some kind of reducing agent and the book gives you 2 different reducing agents and I don't know how I can give you 2 which is more scuffling memorized so wondrously metal it's not zinc chloride clusters just see CNN and use that as a dispersion of zinc powder and in water it's the end product of this it is I feel like it is kind of an easing reaction to 2 senior forward direction because all you do is you sort Split said that carbon-carbon double bonds right down the middle and where you have SEC double bond and is going to be little squiggly line there's students see ozone splits that CC double bond and leads to poverty and that's very powerful sometimes you want a way to generate carbon groups and this is a powerful way to do that but the reaction gets a little harder to see what's going on when you have cycling substrates but this is a very common application and so they take cycle had seen Can I do my ozone analysis reaction 0 3 In this case I'll show you the 2nd type of work of jaw commonly seen our textbook emergencies Smith textbook and the sapling online problem sets in and that is dimethyl sulfide so all drop the chemical structure like this but I almost never draw it out like that I write as any to U.S. is my common abbreviation that's the most common type of Britain abbreviation for di methyl sulfide and it's also a reducing agent on it's it's more reliable than zinc powder the problem is it smells bad I'm more interested in the inefficiency and smells so good the attend the T ask questions where you stand metal sulfide more commonly OK so now is the time for his handling draw this out and 1 of the key challenges for use to recognize what used to be attached to the old so I'm going to drawing the hydrogen is that where that there offense and if you draw everything that's attached opens all the less likely you make a mistake so for example if come over here to my my top case can I remind myself that there were 2 hydrogen is on the double bond beginning with a hydrogen here was a hydrogen down there will be less likely to make a mistake when I drop my product called it if I Drolet there's not that hydrogen is still there and hydrogen is still there and this is 1 way to help you make sure that you draw correctly drawn from it's going to get a little bit crowded into an attractive to those hydrogen but I want to be clear that easily held the hide products that I had to hydrogen is on an outing in the beginning I better see 2 hydrogen atoms in the
product someone OK so so when you ozone Elias cited Albanians the the 2 carbonyl compounds and of attached to each other now if this is not a reaction it's just 4 part of that is just 4 making the hides if I had attaches substituted all fan heads one-sided often had to help groups on it then you end up getting key towns and so here you might be aware that traditionally draw this and so in this case you 2 molecules that are identical both acetone I'm not going to draw the other acetone market you can do that in this case because symmetrical had to have the same product all right so those analysis you know when I when I used to work in the laboratory sometimes human reactions in laboratory instead of getting nice clean reactions you just get brown gunk and we usually refers to those holes all assists I was away because sounds like Lycos analysis and that means you can use that laboratory by reaction the let's talk about what's going on mechanistic way with this ozone gas ozone is very reactive it's great when it's up in the stratosphere that you would not want to sit around in an environment for ozone and does all kinds of things but I'm going to show you what it does in the presence of an outing and it involves a class of reaction is called a parasite quick-reaction specifically concerted cycle edition so we draw the structure of the literature on how keen on going to do my best as sometimes due to emphasize the fact that help teams have 2 different faces and soldiers during Albania's here that to warrants on and then in the back to draw 2 agency can kind of see that there's a top face to this whole affair and so the ozone has a choice just like not elected for regions due to the approach from the top face to the bottom this double so we draw this ozone molecules of ozone is banned those 3 added in the ozone molecules are banned so when I draw my wife was structure I'm not going to draw all the lone pairs on here the 1st contention denied charges 3 bonds to oxygen Haarstad plus charge 1 bond oxygen has to leave my strategy and were never take care to draw this 1 lone parenting oxygen where it true chose to draw minus there's another resident structure could draw on and this is going to undergo a concerted cycle addition reaction in some sense like that allows me to side were simultaneously both carbons of the AL team form bonds with ozone when he drew up arrow pushing for them what I'm going to do that when you take this double bond which is the nuclear file in this collective look oxygen and going to attack that and give the electrons to plus and at the same time that I'm taking electrons away from this carbon over here on the right-hand side I'm to use lone-parent goes on to attack that some simultaneously in this mechanism akin to bonds with that Al-Qaeda substrate to oxygen carbon bonds so that's called a psycho additionally action and you're going to hear a lot about cycle addition actions in Chapter 16 not this kind will will give you a different angle the deals older reaction but in Chapter 16 you'll see more parasites concerted cycle additions fearing it is very very very strange-looking intermediate and the book seems to make a big deal about showing you this mechanism and I'm not entirely clear analysis you because you won't see anything like this ever again in this course of this intermediate call all and I could care less whether you remember the need for that so this species right called the mole ozone I'm intermediate whenever I see oxygen oxygen bonds I think Gee that's unstable with the book does not do is it doesn't explain to you how this clears the carbon-carbon bond bulls analysis is used to clean ECC double bonds at some point in this mechanism we have to cleave the CC double and so there's a transformation occurs that leads to a species called the ozone I'd intermediate is also a five-member ring but as I draw on this new intermediate out you can tell something something very fishy had to happen notice how there is no more carbon-carbon bonds where the help he used to be notice carbon-oxygen bonds good so this is called the ozone identity the intermediate but if excuse me
and this is what would be sitting around until you come along with your benefits all fire is best and sprinkle that endure reaction but the skin and and it was chilly the secret what's happening here and you don't need noticeable doesn't show you this From but I'll show you what's what's happening that's not shown in the book In other words we left wondering what happens in order to convertibles and I Is this undergoes a retro cycle information and on drove mechanisms he can see what's happening a I'm going to miss that I will so if it is not this week oxygen oxygen bond hearing it give the Elektron oxygen and then when uses oxygen oxygen volunteer here swing down and make a double and that's going to induce creation of the mon and if you if you sort of follow through with Myra question I'll get this other very strange weird intermediate you never seen anything like it before that looks like this so what is that it looks a little bit like the ozone that I started got this 3 3 piece here to oxygen and carbon and now that I think if you look here you can see that I had an oxygen carbon species here and I'm not going to flip that around so that now this oxygen is down on the bottom and this are carbon is taking over here on the side and when I do that I can now see how these pieces map onto the overnight and product this doesn't yet another cycle addition
reaction if I draw this out it would look like this text to make an oxygen carbon along the breaks this steel pipe and now these electrons over here can attest that's how you get deals and I'd intermediate is this mechanism is like an extravaganza of cycle additionally actions which would be created expected we've got more chapters before we teach you about cycle editions so very obscure stuff while I'm not sure whether the deal out of this so I'm not going to show you the mechanism for the production this is where you come along with with saying and water or do or die battle sulfide you have to choose 1 or the other if I ask you how you doing knows analysis of somehow and so in the end 1 of these oxygen gets lost in it's completely arbitrary that's what leads to these to Elkins in your product OK so that's handles analysis reaction 0 3 the motive the metal sulfide yes what you question but does this year in this area that I scrawled overcomes from the bomb on this area yeah that's coming from the for the phone unit maintenance question because it suggests has to come so it has to come from the parallel yet he told the others that complementarity electrons on this oxygen so
we fix that so we can see that yes you're right has to come from his longer on oxygen not from the old otherwise would have cleared want so excellent .period yes so you have I can make the Aerostructures along because then there would be no 1 in by coming from a long-term oxygen about it wouldn't hurt to have a Bloomberg outside but
thank you for clarifying that OK so polls analysis so you're using it as a reaction is awaiting the Cardinals and maybe that's not so important now but it's going to be super important when you reach constituency we're going to do a thousand different reactions were you add things to Cardinal groups make C bonds by adding things to carbonyl the so-called on analysis reaction practice in this chapter and be assured that you will be using that when you reach 1050 51 was analysis but there is a little bit affected substantially less common and that is duo's analysis of all kinds most of the reactions that we showed you where you get reactions without you also do reactions with all kinds of theirs in some ways analogous son going to try to take a substrate and all this other spinach earlier side is not really important ideas tired of drawings time the substrate so that come along with this alkaline starting material a treat this with ozone and then I follow that up With the productive work up this is critical you don't want to follow this up with word that worker "quotation mark distributors with water that this leads the oxidation of cleavage always to the carboxyl aghast so none of this other stuff gets gets it is changed and you actually isopropyl them group that now 1 of the problems we just see right here for the the 2 carbons and the current unwanted Indiana kind it converted to a carboxyl gasses In the current on the other hand gets converted into a carboxyl cast and quite often throw 1 1 of the pieces away you isolate both and 1 of them away usually just 1 end of the year of of your molecule is the high-value added molecule don't worry about the mechanism matter and many things about the mechanism for this reaction is it's there's nothing about that's that's useful or extensible to you by U 2 other chemistry that we do this quarter on the 15th series OK so analysis of gives you either elder hides work or key towns on Ando's analysis of all kinds gives you carboxyl again it's OK I we're moving on to what is the most important reactions in this chapter and these by far the reagents itching to know from here forward and I wish I had a green pen unit is all this stuff definition you it'll be on every single 1051 exam in every section that every school that every university and that his oxidation reactions I'm going to show you a series of chromium oxide accidents that are used to convert half alcohols independently and I'm going to show you a series of 4 closely related regions on the 1st year essentially identical on in terms of what they do than the last 1 is different from the start off by drawing out of the 1st created in attracting some different pen colleges interested substrate look at the 1st reading that I'm going to show you this is potassium dichromate emissions the scene elements here to potassium stew chromium 7 oxygen understand what in the heck is going on with that and what's worse I think infinitely worse is that the book also shows you sodium dichromate to so used to chromium 7 there's no functional difference between these 2 there's no reason why you should never worry about what 1 does the identical don't know why the book shows you both sometimes asks you what versus the other that's totally pointless which could draw out the structure of the dichromate 89 it's very similar to a diet phosphate pyroclastic prompted you might see in biology we would drop cruel Maine species what kind of similar here in terms of the structure so here's the 2 Chromium see there's an oxygen bridging those too In each of those chromium says and not an Oxo group looks kind of like a carbon also don't want to go into communist you double bond owes in each promised to all minuses you can see why you need to potassium to Salim's means the balance of those charges on just rectitude potassium down here doesn't affect anything so that's dichromate now when you put solely in every case where we do it in this book when you put sodium dichromate are protesting dichromate in aqueous sulfuric acid it very quickly hired realizes 1 of these oxygen chromium bonds informs a species called from a so in other words you use sodium dichromate the new pro-democracy sulfuric acid build everything you're doing that is because you can't buy from a gas because you can't buy species this is called ,comma again Canada's right here it's unstable you can buy at sea have to make that using cellular companies who make and that unstable the other way that you can make ,comma gas the other regions that you can literally by hand it's a sulfuric acid is chromium trioxide this is a plane archaeologist is chromium with 3 Oxo groups on it and so the formulas is here for a very simple just 0 3 I think you can see that you had H 2 0 that the incoming gas despite molecular formula ways to make ,comma Cassidy Camby ,comma Cassidy could make it from sodium dichromate potassium dichromate or you can make it from prominent and the trickier in all 3 of the men all in both of these cases the trick to making chronic aspect is that you make these things together In sulfuric acid in water so both of these basically generated Chromecast when you put them in sulfuric acid in water and that's really what I want you to remember that there's a 4th species that I want you to remember and I hope you'll see that it looks kind of similar 2 of these other species and this other species and I'm going to show you is called period in coral and you don't need to know you just need to know P C the set to lots of groups the chromium there's no minus sticking out here ,comma like the protests and become minister came back over a year ago the chlorine leaving so that's the coral chromium species the period Damian full there's nothing special about period ending and that's the same species you get when period and acts base in any other action Final Four has just renewed .period so that's the pier that's the P minus other species on lowest that that coral ,comma OK so the most important thing about these reagents it is not related to the chromium Steiger all basically the same crime means that the main thing that you need to remember that this is what solvent to use them invariably when you use PCC you avoid I can't think of any case in my life I've ever seen used in anything other than that ,comma thing you do everything you can to avoid watering PCC reactions on with these other species you're using them in water use in aqueous sulfuric acid but the solvent used this small for these 2 reactor these sets of oxidizing agent is more important than the reagent itself in other words I took PCC and I put it in opera sulfuric acid simply generate Chromecast you'd never put PCC in water otherwise why did you take the time to make PCC if you're simply going to convert converted back into Chromecast but so remember the solvent for these reactions is super important the it's as important as the reagent so it's going to talk about what you can do with the PCC performed do that I want to show you what you can't do with PCC which she may seem odd it may seem odd that I'm going to show you what you can't do with PCs that'll help set us up for selection in With pieces Indian icon resist clinical back because they have to show
you what the whole point of these regions someone just take simple a symbol alcoholic probe all done here and any 1 of these reagents that I just showed sodium dichromate cannot be sulfuric acid chromium trioxide not sulfuric acid PCC and I ,comma thing and I'm not destroyed in brackets indicate oxidation any 1 of those regions will convert an alcohol into 282 and that's the main point here and you will be able to use this as effectively as like to until you get to work until you get to camp 51 C because intended to Muncie will show you how terms carbon-carbon bonds so that's why won't this won't be super-powerful until you get to that stage focus on what's the limitation on there's a limitation and there's little solvents thing you have to remember so let's talk about that so here is a limitation it's no it's such a limitation on its I I feel like it's obvious that you may focus on the fact that former carbon-oxygen double bonds of these oxidation and that's not what I focus on what I'm focused on is the fact that you remove the nature In other words CDs ,comma added .period that's called the carbon all-cargo you need to know the name Cardinal carbon is just a way of saying all the carbon next to the OH group the carbonyl carbon has to have any Johnny but allegedly possibly oxidized so if I treat this with PCC there's no reaction I don't know a China that can be removed and that's really what the oxidant is there is no way to former a CEO double bond unit with 5 months to there's another tertiary alcohol and use that other recipe that I mentioned potassium dichromate become a complex formula cheerful an anemic said in Samarkand sulfuric acid to again I wouldn't do anything there's no wages on the cardinal carbon it's a tertiary alcohols to tertiary articles you can oxidize and to put a ceiling on begin you'd have some weird 5 bonds to cover the situation that would have been crazy so wary of used these chromium oxidants big-money use them Dr oxidizing secondary and primary article in secondary roles in that stock about secondary alcohols and any
1 of those accidents that I showed you what that means that wanted to distance in a moment so he those oxidants that I showed you will work efficiently for converting alcohols secondary articles on the Internet so then you may see what you may see the fact that the new CEO along their something but when I see is the fact that this page document and I hope that that's as plain to use before I drew that is as it was to me so strong 1 of underlying my recipes here just to be different from the chromium trioxide in the sulfuric acid and water In the most organic molecules aren't soluble in water so usually people use acetone is the solvent in that case this is called the Jones oxidation when used in combination of chromium trioxide sulfuric acid water in acetone is the solvent and I hope you don't get exposed you know that no reason to learn that the figures and another substance wherever tertiary call remember what I said that's not going to oxidize and the secondary alcohol and so when and treat this with any 1 of those creative combinations in this case I'll use PCC if I'm encouraging every single time we write PCC to write the solvent if you don't remember the solvent there is no case where where organic chemist used water for PCC so in theory you don't have to write more solvent for PCC
simply assumed to be back on the things but I wish you would write a quorum methane is the sole just to reinforce for yourself that you have this is the 1 of those locks the only 1 of those accidents that doesn't use innocuous coastal so the product of this reaction the tertiary hydroxyl group doesn't get touched still wage but the secondary call that had the H of the cardinal carbon that now gets converted into a key to so tertiary outpost nothing happens secondary to any 1 of those accidents would convert that efficiency into the capital OK so well Perry powerful stuff let's talk about the mechanism and that all talk about what's going on with primary colors primarily foul calls will give you trouble but let's go to a mechanism for what's going on with the chromium oxidation this is a it's a need to elimination not I want to emphasize the book shows you a mechanism for oxidation chromium trioxide is the active species and in which you remember that and none of these acts can actually act through chromium trioxide so and there are some reading on involved from him trioxide In other solvents but nothing in the book gives you is like that so here's the mechanism and I want you to know this mechanism but couldn't stop drawing on alcohol this is going to be a secondary alcohol and I'm going to be super careful to draw their H on the cardinal carbon I'll just exclusively Georgia it's because we're going to pull that this is going to involving the 2 elimination to make our CEO doubled in the 1st step here has to to do with the lone pairs on the alcohol that's a nucleophile and all those chromium oxidizing regions are electrified let me draw out our chromium oxidizing agent and specifically going to give you the mechanism for PCC there's coral chronometers the crummy is the quarrel choral group on the but some minor stress and that's our primary kg with mine and distracted distinguishes 2 arguments focusing considers Socorro ChromaID look at all those elected and chromium chromium wants to be attacked by things 0 look at that uses oxygen known pair Oh my God I hope to get there we go so the hydroxyl group alone there and I got to the fact that the chromium atoms and you kick electrons and I wish I had here in you kick electrons out from this chromium oxygen double bonds and give it to 1 of the oxygen please let's draw this next intermediate the only difference between this and the chronic citizen Chromecast where I had out have a wage OK so this next intermediate is going to be kind of busy now going to literally drawing only going to on there His mature sunlight a secondary alcohol Oh there's now a 3rd bond that oxygen enough to put a positive charge now and look at all these bonds on on chromium my God so complex that I ever sort all this out it's scary look at this to charges on our knowledge of plots on the oxygen that it'll sort out warning so I just made
onto the coral crummy I kick to the electrons up from this box group general minus group an alimony news I'm going to kick out the chloride leading
basically we're just finding a way to do it sometimes has sent to reaction don't displace chloride to to so the drug alone :colon 1 of those 2 minuses and then I'll try to write more carefully with this fact pending here now all fish downward make chromium oxygen double bond again and I'll kick out the course and so when I do that now I once again have to chromium oxygen double bonds His micro meat it's starting to look a little bit simpler now totally simple but I saw the positive charges that oxygen that 3 bonds oxygen you better put a positive charge there and the book there's a for the mechanism for chromium trioxide eventually reached this stage they just as they did this in 1 step instead of 2 steps away editor with pieces the book polls as Proton off but instead of using Arab pressure leaders right-to-work proton transfer if I ask you to write arrow putting mechanisms I want you to show the pushing mechanism for removal of proton on so I'm going to write a species here when you do these reactions with PCC you this period Indiana and stuff and they're unwilling to remedy that he wrote A-minus and also accept that but something to act as a symbolic based under the conjugate base tenacity minus the letter B with a lone pair just something that something symbolic that we can use to pull that Proton off so now essentially what we've done is we've converted this chromium atoms into a a leading when I dropped this next intermediate here and now ready to do the equivalent of the need to elimination at all it looks a little bit similar to things that you've seen before but it's different and all point out why it's different from the other types of 2 elimination what so here's what strange about the 2 elimination it's going to ensue here will reduce miracle of the proton simultaneously this chromium at and what is clear is that the chromium is going to walk away with a pair of electrons with a long pass so now there's going to be something with lone pairs in there but it appeared in nor or some sort of oxygen species is now comes along and does the equivalent of a need to elimination mechanism we pull this Proton off those electrons pushover make sealed along and we did the electrons in this oxygen chromium bond to that reduces that scholar at the end of being a reduction of the chromium so instead of having this orange from me color that you have suddenly go green which is characteristic of chromium oxidation once you reduce the chromium trends we used to be the the basis of these breathalyzer tests please forgive you in the 1980's you breathe in turns green and they know you've had too much ethanol industry your breath OK so the leader of this very strange-looking chromium species you'll never see anything like this again it's now reduced form of chromium all right especially among stroke John OK so so this is the reduced form of the chromium and that's the mechanism of the book mechanism on page 448 is very similar except that they do the 1st 2 steps basically 1 step by adding 2 Chromium trioxide OK so it's in this case there appears to be 2 elimination mechanism not just looked on the 51 LB website if you're taking the attended you did chemistry was very similar do this in the latter half of just highlight how that's similar so in lab you didn't oxidation with bleach were essentially something like this going on you put chlorine leaving group using bleach under Quito and then along came here base and pushed out scoring at incentives same kind of idea all of these oxidation of chromium out of about half of the town's will involve putting some Leading Group on oxygen which is not easy to do so that's what what makes the chromium so magic but it was not primary calls because there's something you would need to memorize it's a distinction between primary
alcohols and secondary articles so is a primary alcohol the 1st thing I see you in my mind the situated on this and I can't resist drawings excuse me while my my irresistible urge to draw those 2 changes when the primary ,comma and this is what distinguishes a primary alcohol from a secondary alcohol and solicitude possible outcomes when we do an oxidation and depends on the solvent we use for chromium oxidation suffused chromium tracts potassium dichromate at the new of course you always do those in water and you have to ride out the water I expect you to the school recipe out the water that's the important facet of the reaction this oxidized is the primary come not to the Kerviel just a simple power behind the oxidizer all the way down to a carboxyl aghast or maybe all the way up and you have to remember that it doesn't stop with just a simple held if you want to stop at the other side you need to go 2 unknown artists created PCC and you don't have to write chorus here but I wish he would write ,comma thing most organic no organic chemistry at the Seoul it's simply isn't it will be on a not solvent and specifically decor everything and so in the case of PCC's stopping over so you get to choose the fear of crime Eric already want just make the other riders whether you want to burn that all the way down to carboxyl gas so and it has everything to do with the solvent it's not the region itself matters here it's the solvent so that's why I expect you to be really picky about this aqueous solid business for potassium dichromate chromium trucks so this is also true of the straight on instead of potassium dichromate you could also use common trackside you'd get the same carboxyl against his result but why isn't this distinction between what these things are doing and why is it that what in water you get 1 result where is in an organic solvent like that ,comma thing you get a completely different result in you not set up to understand this and fortunately the book does not set you up to appreciate why this should be true so I'll show you what's going on here it has to to do with the addition 2 cardinals of nuclear cardinals and the book goes into great immense links to explain this to you when you get to Chapter 21 what the book explains you gently 21 is a variant of the heights water connectors a nuclear not a great 1 to set up a new equilibrium where you have this Adam Cole a hydrant where you add the element of water and I'm not going to draw the mechanism is not 1 step mechanism it's a multistep mechanism but whenever you put aldehydes in water you also have some of this Our die hydroxy this is called the Hydra you also know that this hydrate floating around and typically for most held behind this ratio is about 1 to 1 inch street life so we call this the height-adjustable air here this is called hydrated I hope you can see that the hydrate looks kind of like an alcohol it looks kind of like the secondary article and it's it's not like it's frozen in space here this is a rapid back-and-forth equilibrium and so what's happening here is any when you do oxidation of primary alcohols "quotation mark Is that the outside its present in water forms a hydrated and the hydrate undergoes an oxidation reactions so there is a just redrawn high-grade are slightly different way so that you know as you can see the H on the hydrate carbon since this does the same oxidation business that I just showed you and doesn't really matter what the chromium species is here the some Leading Group on the chromium species whether it's a wage you need to know that this kind of mechanism here so the point is you get to the same stage that we are for it doesn't matter this other group is it is an OH still reached the same stage in your mechanisms he still undergo the same type of E elimination and the only real difference here is that hydroxyl groups thinking on the part of you still get to this stage where does some sort of lead to elimination and that's what leads to the crux of the castle you still get the lone pairs to chromium so when you reach Chapter 21 and 1051 see this whole hydrated business in additional water to held a highly completely natural to you at this stage now I kind of expected it to be a little bit mysterious to me so I just hold on this stuff right here this hold on for Chapter 21 if you'd like to read ahead gold it's more explanation of all the things that I had to do fantastic work but that's why you can't stop elder hides from forming hydrogen water and it's the hydrate and that's actually undergoing oxidation to the conduct of and if using PCC in decorum methane or there's no water intake or anything so you can formally hydrogen and that's why the soldiers so critical OK so the last part of the of Chapter 12 there is a section called green chemistry in ethanol and what they don't you can take chromium regions and awarded them onto solid supports and they say that this is green chemistry on environmentally-friendly chemistry on you know chromium 6 species of Class 3 shit carcinogens the Occupational Health and Safety Administration labels carcinogen I don't consider that to be green chemistry and something to say Michigan where the whole sections the 2 move forwards the last section there's something called the shop was of oxidation and last the last time I talked with classes many years ago for years ago maybe I went through this and we ended up spending 90 per cent of our discussion sections in office hours going through this over and over to the point where I can tell now that this reaction does not merit this much attention this is 1 of the 1st reactions that allows you cancel images clarify I'm not going to put this on my hands there was a time about 25 years ago when was this was basically the only reliable asymmetric reaction you could do we could particularly in light of the Internet also versus the other but that was 25 years ago and we now have zillions of highly efficient reactions and like 1 intimate or the other in a predictable fashion but and there's no reason why you should have to memorize this outdated reaction which was historically important land but now has been complemented by such a vast number of actions here's what the reaction does this is called a show of support sensational show you the recipe and maybe you can get a sense here's what I want to show you this you know not putting on minds and I expect you to work each every problem in the back chapters expect you at every single problem you want to get experience working problems you've never seen before and unfortunately some of the problems in the in the back of a chapter involved as shoppers approximation in releasing the workers are the sharpness of oxidation involves taking TB Hydro peroxide so it's not too you know there a a whole lot better Hydro peroxide so this is the accident and the reaction from the point of the show was approximation is that you can use it to get a single and the engine of the parts Parkside MCP PBA would do exactly the same reaction would give you is receiving mixture on this reaction gives you out just a single engine parts and I don't feel like it's important for you to remember with changes and go through a lot of work to memorize which ancient get that does not seem useful in any way so you used to be a lot of peroxide so you can see where the oxygen atom in the epoxy is coming from yes you can do the same thing with CPB Garrison mixture then you need a catalyst it's this tightening catalyst which will supervise curious to you so you for ISO proxy groups the right ISO protocol Oxy here that's the catalyst for the reaction and then you put in this car will have a difficult time of Excuse me die of old territory on and I'm simply wonder really flustered efforts territories a single Indian tumor of a naturally occurring dialog this compromise infusion to memorize that this recipe from diffuse the opposite tumor at Eiffel Tower trade with also readily available but you get together in the interior of the epoxy tonight doesn't sing from Fulton on throughout the whole territory for you but that this was a major medical territory looks like this it's an this Esther and those 2 which groups gripped the Titaniums to create a Cairo environment so sold so I encourage your problems in the back of Chapter 12 some of those problems will involve this shows approximation of what that so when we come back on Friday learn asserts that cost containment spend the summer want to weeks just talking about spectroscopy and so steel yourself
Chemische Forschung
Halluzinogen
Applikation <Medizin>
Setzen <Verfahrenstechnik>
Körpertemperatur
Flüssigkeitsfilm
Rauschgift
Knoten <Chemie>
Chemische Verbindungen
Computeranimation
Energiearmes Lebensmittel
Pharmazeutische Technologie
Rauschgift
Pille
Appetit
Körpergewicht
Vancomycin
Körpergewicht
Hope <Diamant>
Gen
Energiearmes Lebensmittel
Primärstoffwechsel
Single electron transfer
Metallatom
Stoffwechselweg
Dimethylsulfid
Wasser
Ozon
Puder
Stickstoff
Computeranimation
Doppelbindung
Rauschgift
Spaltfläche
Induktor
Membranproteine
Reaktionsmechanismus
Chemische Bindung
Atomcluster
Sulfide
Signalkette
Substrat <Chemie>
Dispersion
Zinkchlorid
Reglersubstanz
Organische Verbindungen
Zelle
Ethan
Reaktionsführung
Zink
Kohlenstoffgruppe
Epoxidharz
Zelle
Brandsilber
Toll-like-Rezeptoren
Hydroxylierung
Gen
Körpergewicht
Prädisposition
Cytologie
Chemische Forschung
Hydroxylgruppe
Spanbarkeit
Besprechung/Interview
Transkriptionsfaktor
Fluoralkene
Lösung
Ozon
Chemische Struktur
Sekundärstruktur
Leukozytenultrafiltrat
Allmende
Weibliche Tote
Systemische Therapie <Pharmakologie>
Aktives Zentrum
Inhibitor
Hydrierung
Setzen <Verfahrenstechnik>
Gangart <Erzlagerstätte>
Tank
Fluoralkene
Magma
Energiearmes Lebensmittel
Azokupplung
Ultraviolettspektrum
Sekret
Methanol
Vancomycin
Sandstein
Hope <Diamant>
Redoxsystem
Sauerstoffverbindungen
Laichgewässer
Feuer
Transformation <Genetik>
Kohlenstofffaser
Besprechung/Interview
Reaktionsmechanismus
Konvertierung
Chemische Forschung
Ozon
Fluoralkene
Computeranimation
Doppelbindung
Aceton
Ozon
Spaltfläche
Chemische Struktur
Spezies <Chemie>
Additionsreaktion
Sense
Reaktionsmechanismus
Wildbach
Chemische Bindung
Sammler <Technik>
Carbonylgruppe
Ozonide
Molekül
Funktionelle Gruppe
Energiearmes Lebensmittel
Ethan
Elektron <Legierung>
Reaktionsführung
Einsames Elektronenpaar
Ausgangsgestein
Cycloaddition
CHARGE-Assoziation
Parasitismus
Thermoformen
Vancomycin
Katalysator
Redoxsystem
Sauerstoffverbindungen
Pipette
Metallatom
Fülle <Speise>
Elektron <Legierung>
Stahl
Reaktionsführung
Querprofil
Kohlenstofffaser
Besprechung/Interview
Reaktionsmechanismus
Chemische Forschung
Konvertierung
Wasser
Computeranimation
Cycloaddition
Spaltfläche
Blei-208
Reaktionsmechanismus
Vancomycin
Ozonide
Sulfide
Weibliche Tote
Redoxsystem
Sauerstoffverbindungen
Gensonde
Stereoselektivität
Single electron transfer
Alkohol
Heck-Reaktion
Emissionsspektrum
Tetrahydrothiophen
Lösungsmittel
Bukett <Wein>
Reaktionsmechanismus
Konvertierung
Wasser
Ozon
Doppelbindung
Spaltfläche
Spezies <Chemie>
Chlor
Cyclopentadien
Redoxsystem
Reaktionsmechanismus
Chemische Bindung
Carbonylgruppe
Vorlesung/Konferenz
Molekül
Lactitol
Alkalität
Carboxylierung
Substrat <Chemie>
Kalium
Fleischersatz
Fülle <Speise>
Reaktionsführung
Symptomatologie
Oxidschicht
Entzündung
Base
Selenite
Wassertropfen
Phosphate
Periodate
Vimentin
Hydroxylgruppe
Chemische Forschung
Kohlenstofffaser
Besprechung/Interview
Mindestzündenergie
Chemische Forschung
Alkohol
Chromoxide
Strom
Reaktionsgleichung
Stockfisch
Ozon
Chemische Struktur
Cadmiumsulfid
Penning-Käfig
Funktionelle Gruppe
Chrom
Wässrige Lösung
Lösungsmittel
Schweflige Säure
Oxidans
Chemischer Reaktor
Kaliumdichromat
Natrium
Dichromate
Energiearmes Lebensmittel
Säure
CHARGE-Assoziation
Chemische Formel
Vancomycin
Chrom
Chemisches Element
Redoxsystem
Sauerstoffverbindungen
Methanisierung
Hydroxylgruppe
Alkohol
Chromate
Kohlenstofffaser
Besprechung/Interview
Küstengebiet
Reaktionsmechanismus
Chemische Forschung
Wasser
Alkohol
Chromoxide
Doppelbindung
Aceton
Chronische Krankheit
Reaktionsmechanismus
Chemische Bindung
Sekundärstruktur
Vorlesung/Konferenz
Molekül
Funktionelle Gruppe
Terminations-Codon
Chrom
Fluid catalytic cracking
Organische Verbindungen
Lösungsmittel
Schweflige Säure
Fülle <Speise>
Elektron <Legierung>
Reaktionsführung
Einsames Elektronenpaar
Oxidschicht
Potenz <Homöopathie>
Amine
Mähdrescher
Gangart <Erzlagerstätte>
Eliminierungsreaktion <alpha->
Ester
Ordnungszahl
Schubspannung
CHARGE-Assoziation
Eliminierungsreaktion
Ketone
Vancomycin
Chrom
Redoxsystem
Sauerstoffverbindungen
Alcotest
Reaktionsmechanismus
Frischfleisch
Computeranimation
Doppelbindung
Rauschgift
Spezies <Chemie>
Chlor
Laichgewässer
Reaktionsmechanismus
Chemische Bindung
Fülle <Speise>
Elektron <Legierung>
Reaktionsführung
Symptomatologie
Oxidschicht
Base
Ordnungszahl
Selenite
Ester
Ethanol
Protonierung
Bleichen
Eliminierungsreaktion
Thermoformen
Periodate
Chemische Forschung
Chloride
Chromate
Besprechung/Interview
Chemische Forschung
Druckausgleich
Alkohol
Chromoxide
Orangensaft
Aceton
Reduktionsmittel
Elektronentransfer
Funktionelle Gruppe
Chrom
Konjugate
Einsames Elektronenpaar
Setzen <Verfahrenstechnik>
Gangart <Erzlagerstätte>
Eliminierungsreaktion <alpha->
Farbenindustrie
Vancomycin
Chrom
Redoxsystem
Sauerstoffverbindungen
Biosynthese
Alkohol
Sharpless-Epoxidation
Bukett <Wein>
Reaktionsmechanismus
Isotopenmarkierung
Wasser
Computeranimation
Spezies <Chemie>
Redoxsystem
Sense
Reaktionsmechanismus
Aldehyde
Lactitol
Terminations-Codon
Carboxylierung
Organische Verbindungen
Fülle <Speise>
Grüne Chemie
Reaktionsführung
Carcinogen
Chiralität <Chemie>
Stereospezifische Reaktion
Oxidschicht
Epoxidharz
Peroxide
Ethanol
Chemische Reaktion
Mischen
Thermoformen
Hydrate
Advanced glycosylation end products
Nomifensin
Hydroxylgruppe
Chemische Forschung
Methanisierung
Carboxylate
Tumor
Titanchloride
Aldehyde
Kohlenstofffaser
Besprechung/Interview
Hydroxyethylcellulosen
Alkohol
Chromoxide
Hydrate
Epidermaler Wachstumsfaktor
Additionsreaktion
Natriumdiethyldithiocarbamat
Funktionelle Gruppe
Containment <Gentechnologie>
Weibliche Tote
Chrom
Wässrige Lösung
Allylverbindungen
Hydrierung
Stahl
Einsames Elektronenpaar
Polymorphismus
Potenz <Homöopathie>
Setzen <Verfahrenstechnik>
Kaliumdichromat
Gangart <Erzlagerstätte>
Eliminierungsreaktion <alpha->
Dichromate
Säure
Blei-208
Vancomycin
Chemisches Element
Redoxsystem
Adamantan
Sauerstoffverbindungen

Metadaten

Formale Metadaten

Titel Lecture 15. Reduction and Oxidation, Part 3
Serientitel Chemistry 51B: Organic Chemistry
Teil 15
Anzahl der Teile 26
Autor Vranken, David Van
Lizenz CC-Namensnennung 3.0 Unported:
Sie dürfen das Werk bzw. den Inhalt zu jedem legalen Zweck nutzen, verändern und in unveränderter oder veränderter Form vervielfältigen, verbreiten und öffentlich zugänglich machen, sofern Sie den Namen des Autors/Rechteinhabers in der von ihm festgelegten Weise nennen.
DOI 10.5446/19484
Herausgeber University of California Irvine (UCI)
Erscheinungsjahr 2013
Sprache Englisch

Inhaltliche Metadaten

Fachgebiet Chemie
Abstract This is the second quarter of the organic chemistry series. Topics covered include: Fundamental concepts relating to carbon compounds with emphasis on structural theory and the nature of chemical bonding, stereochemistry, reaction mechanisms, and spectroscopic, physical, and chemical properties of the principal classes of carbon compounds. This video is part of a 26-lecture undergraduate-level course titled "Organic Chemistry" taught at UC Irvine by Professor David Van Vranken. Index of Topics: 00:09- Canker sore drug helps mice lose weight 01:37- Amlexanoxx 04:00- 12.10: Ozonolysis of Alkenes with Ozone 10:24- 12.10: Oxidative Cleavage of Alkenes 18:22- 12.11: Oxidative Cleavage of Alkynes with Ozone 20:33- 12.12A, 12.12B: Chromium Oxidant Recipes 26:52- 21.12A, 12.12B: No Oxidation of Tertiary Alcohols 29:48- 12.12A, 12.12B: Oxidation of Secondary Alcohols to Ketones 32:32- 12.12A, 12.12B: Mechanism for Oxidation of Alcohols 40:30- 12.12A, 12.12B: Oxidation of Primary Alcohols 43:12- 12.12A, 12.12B: Why Primary Alcohols Oxidize to Carboxylic Acids in H20 46:48- 12.13: Green Chemistry, Ethanol 47:27- 12.15: Sharpless Epoxidation

Zugehöriges Material

Ähnliche Filme

Loading...