Lecture 08. Alkenes, Part 3

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Lecture 08. Alkenes, Part 3
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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: 00:07- Foul smell complaints in southern England after gas leak 00:51- Mercaptans stink 02:23- The Lubrizol plant map 04:03- 10.8: Addition of Electrophiles to Alkenes 5:44- 10.12: Hydration: Acid-Catalyzed Addition of H2O 09:49- 0.12: Hydration: Acid-Catalyzed Addition of H20 15:30- 10.13: Halogenation: Addition of Br2 and Cl2 18:26- 10.13: Mechanism Involves a 3-Membered Ring Halonium Ion 25:28- 10.14: Stereochemistry of Halogenation 30:44- 10.14: Halogenation Stereochemistry 36:08- 10.15: Halohydrin Formation: Halogenation in Water 40:54- 10.15: Halohydrin Formation: Halogenation in Water-Steps
Area Agriculture Vancomycin Chemical compound Chemical plant Biofouling Leak Man page
Wood-burning stove Sense District Ethylgruppe Steel Sulfur Wursthülle River source Leak Multiprotein complex Reactivity (chemistry) Clenbuterol Mercury (element) Stem cell Vancomycin Invar Beer bottle Chemical plant Chemical compound Natural gas Aage ISO-Komplex-Heilweise Stuffing
Semiotics Calcium hydroxide Chemistry Molecule Ethanol Benzene Periodate Filler (materials) Doppelbindung Mineral hydration Tuberculosis Walking Chemical reaction Alcohol Lone pair Reducing agent Vancomycin Acid Pleuramesotheliom Cobaltoxide Sense District Species Reaction mechanism Wursthülle Acid Propionaldehyd Man page Origin of replication Ageing Magnetometer Schweflige Säure Conjugated system Process (computing) Setzen <Verfahrenstechnik> Atom probe Tumor Phase (waves) Asset Carbon (fiber) Protonation Alkene Water Hydrate Drop (liquid) Functional group Iron Hydroformylation Substrat <Chemie> Base (chemistry)
Area Species Reaction mechanism Doppelbindung Dehydration reaction Mineral hydration Protonation Chemical reaction Wursthülle Alcohol Wine tasting descriptors Man page Hydrate Water Vancomycin Acid Electron Ageing Azo coupling Schweflige Säure Dehydration reaction Cobaltoxide
Chlorine Atomic number Calcium hydroxide Chemistry Electron Cycloalkane Organic food Substituent Doppelbindung Walking Chemical reaction Electronic cigarette Mauveine Lone pair Vancomycin Optische Analyse Dominican Republic Hydroxybuttersäure <gamma-> Chemical compound Bromine Cobaltoxide Thermoforming Biomolecular structure Starvation response Sense District Kohlenstoff-14 Ionenbindung Species Reaction mechanism Economic sector Wursthülle Man page Ammonium Magnetometer Common land Faserplatte Pain Halogen Chemical reactor Molecularity Bromide Fluorine Nitrogen fixation Carbon (fiber) Iodine Protonation Water Valenzelektron Epoxidharz Functional group Nitrosamine S-Adenosyl methionine Ammonia
Atomic number Chemistry Molecule Electron Singer Corporation Cycloalkane Substituent Doppelbindung Mashing Walking Chemist Chemical reaction Electronic cigarette Vancomycin Pleuramesotheliom Azo coupling Bromine Medical history Thermoforming Ionenbindung Quaternary ammonium cation Sodium hydride Reaction mechanism Ice sheet Wursthülle Methylgruppe Man page Ammonium Ageing Active site Pleuramesotheliom Hashish International Nonproprietary Name Mixture Atom Mineral Halogen Chemical reactor Setzen <Verfahrenstechnik> Area Molecularity Selenite Phase (waves) Tumor Arginine Bromide Malerfarbe Carbon (fiber) Functional group Medroxyprogesterone Substrat <Chemie> Farmer
Semiotics Bohrium Hydro Tasmania Collision Chlorine Chemistry Molecule Electron Periodate Hydrophobic effect Germanic peoples Doppelbindung Chemical reaction River source Alcohol Electronic cigarette Hydroxide Lone pair Vancomycin Acid Optische Analyse Bromine Medical history Stuffing Ionenbindung Kohlenstoff-14 Reaction mechanism Substitutionsreaktion Hydroxyl Wursthülle Man page Ammonium Ageing Active site Exciter (effect) Ausgangsgestein Halogen Oxide Process (computing) Setzen <Verfahrenstechnik> Atom probe Molecularity Selenite Phase (waves) Bromide Carbon (fiber) Adamantane Protonation Hybridisierung <Chemie> Man page Water Hydrate Initiation (chemistry) Radical (chemistry) Iron Pharmaceutical drug Chemical structure Substrat <Chemie> Ammonia
makes up for the Nick Sizemore turned me on to this this recent news stories on England there were a lot of residents were starting the plane to complain about a very bad smell on and was very quite widespread areas Hampshire Dorset Oxfordshire Northampton farms and the leak was blamed on a chemical factory in ruined and the gas they say that was causing the smell of the captain and so I want to talk about mercaptan the trade introduces selves to this class of compounds which I really associated with on various strongly with 1 word and
that is the case smell that so there is no actual compound called the captain and the captain is actually a class of compounds and in modern nomenclature recalled captain styles anemic captain comes from the fact that I formed very strong complexes with mercury and so usually given mercury spill U.S. sulfur compounds to stick to the mercury at the atomic level and clean those of messes up on produced 2 of the most common of tends to most common files so it really you have ever smelled natural gas like maybe left the stove on too long already source of gas in the house it stinks really badly which is great because you don't want sit in housecleaning natural gas you never actually read the smell of natural gas which is smelling former captains the admiral captaincy and files to the natural gas so that it will smell so bad that you won't stay in a room with natural gas leaks in the arm and what they do is they take the natural gas and they it in on about 1 to 1 million ratio at these compounds there so potent on that you can't possibly bear to be be in the vicinity of so we don't use the term that nowhere in the book to use the term accountants old compound archaic compound or sort on old name interconnecting all use the words by all in this class to discuss this class of compounds on just to give you a sense for the potency of files and the smell and usually a little now
because if you're not included in the town of Rowan is not in England it's in France so the Lubrizol factory was down here so this is the continent of Europe and the smell wafted all the way over here to England on for all these residents had personality convention the potency of these compounds and I can't even begin to imagine how bad it was for the people living in northern France here on the cost English were the ones who are complaining the most because they didn't create this OK so long steel military furor smell on mercaptan erectile complements the smallest skunks that's the smell of rotting eggs and really atrocious stuff and that's the smell you smell and natural gas OK let's return back to hold .period awarded of women exam next Friday so it's Friday today 1 week from today is that in this room a have exam so what their leaders were Monday had extra office hours next week the lovers our posted on the court's website so you can refer to that but in addition of that means we're not going to have discussion sections next Friday so when you are in a Friday discussion section go today but next week to find a different discussion section to go to because we would have discussion section next Friday in it will tell you is much greater discretion 2nd after the exam so forget about a discussion sections none of those next week I go to different discussion section of the an endless discussions at times are also posted on the court's website OK so it's come back to lecture on how knocking reactivity so this is not
an Irish only the life sometime ago I said Chapter 10 is not by reactions we're going to take my reactions in so many different ways with obliging you with those reactions on so we spend all our time so far just discussing this 1 reaction the addition of a R and hypothetically HIT to C C double monster reduction of this period chemistry the fact that you can have the protons from the top place in the final phase of the CCW on the talk about the fact that want to create a cargo carrier the nucleophile contact from the bottom face to the top place so we all these big deals about the fact that there's 2 different faces to the there's 2 different faces to Aqaba and now we're going to spend the next 2 lectures on that Saturday and Monday talking about these next 4 reactions in detail on so because we have on our last lecture in Chapter 10 on Monday I extended the deadline for the 1st problems at the sampling work until Monday nite so you don't have to finish that by Sunday have until Monday because I will finish on the last lecture probably OneDrive orations on Monday and then there's a note on the Sabine website saying that the deadline was extended to Monday nite from Sunday OK so let's talk about it that's come back to these reactions without these other 4 reactions number 2 through 4 here that we wanna know something about in detailed mechanistic and I know I won't need to go in as much detail into as much detail now to spend some time talking about the addition of of Ajax HBR HCL or things like that OK so you can have Hi that since across the seat of a once on the reaction starts up approximation trying to do the same thing with water the water is not very acidic so we add an extra acid you have to add an extra acid when you do these reactions of water otherwise reaction just won't go and so the pattern you need to recognize is that if you take a double bond and admits that around with from stood around in and yet other sulfuric acid is a catalyst you add water across the doubled while you had 1808 across a couple of on the public can see dates that I had added because we typically don't draw pictures of fraud for you here just you can see there's the H from the water and I think you can see way water so this is very hard reaction to see just like additionally the oxygen can typically see where the protons into on and cheering at work enough problems to where you're used to that on the type of Compaq OK so that if we did the same thing down below Matichon expert at this hydration is what we call it acid catalyzed additional waters hydration and that some sort of makes sense with the name so now it's still hadn't talk of applied reaction to this substrate and I use pH is an abbreviation for a benzene ring for a final group solid pH down and so based on what I just showed you I had a wage down here and I had a job above notice I didn't create a spirited etc. In this particular case I chose molecules that would not be unused originate centers is known in tumors in this case ,comma a good draw you don't have to draw the age but I just like to show you where that each week to see conceived the I added 1808 aggressive that hydration and you need an acid catalyst in this work Water is not acidic enough to make his reaction work so let me admonish you not to believe that every single as it is the saying because I do not I will count you wrong if you use don't use HCL age we RHI freer assets I just showed you in the previous lecture what happens if you had HCL and HBO on each eye of floating around with double bonds so the problem with these is that these counter on things like or With its lone pairs Verone lies with its lone pairs iodide with his long years all 3 of those counteracted nucleophilic and the last thing on the planet which you want is another nucleophile floating around in this reaction so that's why you don't want to use those acid you want to use sulfuric acid far as I know that's the only reaction anymore the only acid we'll show you usually use for acid catalyzed hydration on so in contrast the just so why is it that you sulfuric acid we going drop the counter for Monaco Monaco deep-rooted native animals that form of sulfuric acid that called the Beisel 389 iron you need to know that terminology so sold 89 has been really very very very low nuclear Felicity when the decision no nuclear Felicity if sulfate accidentally added to Aqaba that I would probably have to get and for realize that's not the case it's not as fast them the pot back out of cases sulfate is super non-nuclear filler and a super good leaving Group and so that's why you can get away with sulfuric acid and don't use any of those arrested OK so it's a pretty easy idea in terms of the pattern adding H in some nuclear power across a double bond ,comma it's kind of like HP already HCL and potentially jibe that's not use during much because let's talk about the mechanism for this edition of water across a double bond it is the mechanism is going to be very similar on to the mechanism that I showed you for asked for asked for the addition of HP or earlier this good draw of a mechanism year of wouldn't take a substrate that's I that is not symmetrical we get Marconnet competition with additional water and the reason why follows McConnell hospital where were you from Meet the less substituted double bond in the nucleophile ends up on the more substituted carbon that is is because we're going to generate public and I'm so the 1st step in this reaction mechanism among the probe made the double bonds and I'm going to symbolize my acid sulfuric acid or whatever it is there's lots of acidic species floating around him the symbolize those with this HA and I'm going to use that for my hero question so the 1st step is for for some acidic feces to come along and dumb and that that double bonds .period my hero from the middle of the double bond attacked the protons and displays the A-minus counter and so now when I get my intermediates there's no proton attached and surmount here's my true cover that that's lovely if I protonated and you can't tell what put the proton it's sort of invisible now because organic don't draw the job for you here just to consumer needs my little can cause I don't want to overemphasize OK so that's where the protons into and leaves behind tertiary care and I did not have the Proton to the bottom carbon because that would have let me with this Southeast secondary character and you don't want it generates up the secondary contracts and now we get this cargo can iron and if you're in the presence of water or any
alcohol In sound images generated doesn't have to be water they could be ethanol propane all something more complex if you want you can replace the ROH still looks like a real hydration and Gates analysis discovered Canada's floating around and you already know the rest of this we spent a lot of time talking about the chemistry of alcohols on an uncle's attack in Kabul Caroline's in Chapter 9 and so when you attack I now have this oxygen attached to carbon the Proton is still there 3 balanced oxygen that means she has had a positive charge not-so-new Oxo only means oxygen 3 bombs on and so now I can use that calendar the conjugate base from has that A-minus is still floating around is my mind was floating around in the previous definite simply didn't drew draw that OK so there's my conjugate base from that original HA symbol passes and so simply news that to recapture the
protection of deep-rooted make that mine in give the electrons back oxygen which is electronic so this is what we do to your final product in this case if if you're adding an out call you and getting the there a few adding water you end up getting but in this case a tertiary alcohols OK so a couple of notes about this reaction mechanism so this is the mechanism in this case it is the reverse of acid catalyzed dehydration that we saw in Chapter 9 so back in Chapter 9 we should a mechanism for adding acid sulfuric acid to alcohols and eliminating to give double bonds it was a three-step mechanisms just like this is a three-step mechanism the reaction diagram had 3 homes just like the reaction .period diagram has has 3 hunts for this so it's the same mechanism mechanism on just the reverse as acid catalyzed dehydration so trickster this again notice in my mechanism on abbreviating mining acid a check now could you draw mechanism using sulfuric acid rather than writing change in theory you could the problem is once this reaction starts going you have all kinds of acidic species is floating around in your reaction mixture you got sulfuric acid floating around in your reaction mixture you got from needed Water floating around in your reaction mixture or premiered alcohols you don't actually know which of these 2 species is donating protons to the outside when you have acid in the presence of articles and very instantaneously creates this equilibrium between programming alcohol and having the proton on the sulfuric acid so because you don't know what's probably knocking that might better symbolize the acid with age and I think it's simpler to write a check to write these other things that probably so OK so well so acid catalyzed additional water or alcohols conducts the mechanisms OK so they can do because we covered the adverse reactions in so much detail we don't need to make a big deal about hydration irradiation of 1808 across-the-board once so let's stick to the 3rd of those 5 reactions were undercover and again this is very similar to the addition of HBO are in HCl and that's you generate a couple can find something and still but this is the 3rd of those 5 reactions were going to come totally new and exciting because this is different from that each so water in some areas already had
a discussion sections and in practice in using these these new
reactions so when you add halogen molecular bromine unlike chlorine your too aggressive double bond each carbon and the double bond it's allergies and should you choose show simpler example of this reaction to the article simple healthy and the reason why I consider this to be a simple example Is it when I had the authority to those 2 carbon atoms in the office I don't create security antics centers is a simple life the application of this on but things can become a little bit more difficult if we have to worry about stereo chemistry consulting compound down below here and there's a double bond to oxygen doesn't do anything I just put that in this example as entire herd drawing simple and so now we have to pay attention to the stereo chemistry we have to worry about whether the 2 chlorine atoms scoring acts a grant to the two-point Adams at the same face of the double bond ordered the end opposite faces are we going to get a seat in the mode of edition or immunity motive edition what are the 2 points going to the scene to each other warranty to each other in the product and for this particular reaction they end up being emptied every single time so that's an empty relationship others right down and I'll explain the mechanistic Lee why you getting into on very shortly so course I generated 2 ministerial unique centers here the other product don't get is the mirror image which will also be handy but it's going to be the manager that and that arises from the fact that the well the you can't control the reagent doesn't know what to form 100 nervous versus the OK I will never ask you what happens if you had fluorine molecular fluorine Orion into a double bond on and that's because those reactions don't work for you will just have you a lot of a lot of pain and anguish and iodine simply the equilibrium is just favorable for additional lied to cross a double 1 the bromine and chlorine are the only ones you have to worry about for this section and other useful reaction promise you don't use them in this chapter and I promise you that using actually all these reactions you learned throughout the rest of public can 51 organic instances OK let's talk about the mechanism this reaction because it's different from to on water HP on water both started with the addition of a proton on to a double wants to give cobbler and this reaction does not involve a cargo carrier OK so it's a two-step reaction mechanism and again this this is a super important point here because the 1 you're familiar with now forms cargo can and there's no Carver reactions with strong what our reaction here and then try to draw and going to struggle here too drawn out he's sort of a John With a three-dimensional kind of look 1 of the 1 of the substituent on my help people the sticking out of the Board of my paper and then the other substantial of the kind of sticking back and will try to imagine what happens is my molecular bromine and into a rumination action comes down in approaches from the top of the Saudis so let me draw my so which had left a little more room here here's 1 of the and here's the other bromine she's I wish I had left more because the bromine providers long that's what makes it so reactor which had left a lot of room because I would've freakishly distorted that bromine growing Bonte looks very long OK so so that Keane has electrons and connects the nuclear file and you know that bromide is a good leading group so I hope you won't be surprised when I tell you that the double bond is going to attack that Proton but it's going to attack the bromine hadn't yet seen that before and you're going be AA-minus act is a leading you have seen that before so what hear is that you're attacking the bromine atoms but when you know you haven't seen had only disposed be leading group when you attack bromine well when you have a bromide leading group attached but the other part of this is because there is this pair of electrons which draw some of the valence electrons on this 1 is bromine near the bottom restraint pick lone pairs on the bottom bromine and has this double bond is coming up to attack the bromine it's taking electrons away from 1 of the carbon atoms here taking electrons away from 1 of these carbon atoms and that is you're doing that these lone pairs courtesy that public and I'm forms again and I feel I can do something about that what what do simple is another word you don't former a Oregon as you start to take away electrons away from 1 of the carbon the bromine long given back so instead of generating a cobbled Caroline intermediate in this case were going to generate a three-member arena species that you haven't seen before this is the way it works be R 2 and C O 2 and there's still a lone
pairs here those are really consequential so you have a positive charge bromine and so this is called of ammonia I understand that only year what is it that makes sense of ammonia mind it's not the fact that it's worth remembering is affected territory bonds to when there's 2 bombs to remain there after the positive charge by bromine only has 1 by but there's 2 bond you need a positive charge and bromine and this particular Ramon E. minus is happens to be sigh in the three-member review so while that special you've already seen reactions involved three-member rains and positively charged when you permeated a pox so here permeated bemoaning mind intermediate common redraw this ammonia mind intermediate on instead of continuing my here I'm going to redraw that that money mine because I want to emphasize what is called a step 1 in local this down year step 2 and the reason I want to redraw the sp ammonia intermediate as it is I want to on conveyed this idea to you and I'm going to really distort this so it'll be memorable my point here not necessarily showing something that's perfectly accurate but I wanted distorted to remind you that 1 of these bonds is almost free broken if I drove like this maybe you'll remember what I'm trying to do is make it to the 1 these bonds to the monument Adams is really long and ready to break at a moment's notice there the other the bond between this primary carbon atoms it is about to break anytime soon so this is the way of ammonium ion that some Israeli calls here and distracted depicted in this freakishly distorted way and so now what happens is that when the bromine counter this year furious comes in it doesn't attack this nice short bond here it attacks this kind of pretty broken bonds to the tertiary sector and what's important is that this is yet another example of the nascent you reaction a tertiary Sanders we already showed you that you do ask that you always U.S. into reactions to tertiary centers with coordinated epoxy without Sonia mines and three-member grants
you do as into it tertiary centers and so here's another example of another three-member during on who with but that tertiary sentence and so in the end we've now got 2 different bromine atoms attached and they added from opposite faces of the Al-Qaeda they have to wary you have ammonium ion like this the bromine atom in the bemoaning miners on 1 face of where the outing was and the B -minus coming from the opposite side so you have to end up with this overall in motive of edition on the cost of the product they can swim all around this this carbon-carbon bond but the 2 remains ad from opposite faces so that's why you end up with this painting motive edition because it goes to enhance into reaction of ammonium and and others were destined to because we may be uncomfortable writing it into a tertiary centers but not with three-member greens in positive charge OK so so that the mechanism there's 2 steps so this very weird edition of bromine to make of Romani minded history heroes 3 Kerberos and then assess into opening up of the the breached OK so it's all walked through some examples that will allow us to see this what it wants the stereo chemical implications of this idea that we form of ammonium ion and the bromide on Popsicle opened from the outside practice that on some substrates here see if we really if we really get this the R 2 additional the addition of groaning so here a reaction of just a very simple help and I'm going to draw the product of this so typically online work sheets and my exams I think most faculty members of example there's a reaction an empty box and you write the product in the box so what I expected a right so what's the answer you need to write for a case like this will going add 1 bromine onto 1 of the province and then we going add another bromine atom to another ,comma but you have to pay super close attention to the fact that you just created a sterigenics center right here and arbitrarily going to draw this with the way coming out of
this there's not another each it's going back so this is 1 an anti-American is forming reaction also won the other this endangerment forms because the initial Baroni added from on this case the back face in the beyond Bahamas attacks from from the top but it's just as likely but the will get the opposite motive edition In terms of which face the reactor of the whole often reacts say also that this other than tumor and if you don't feel like drawing Mediterranean tuna you can simply write clustered in my class we will understand that to mean that you are receiving mixture 1 1 Of the 2 endangers the two-year images of the product in this class so I I typically Wallstreet right simply like this possibly say plus and we all understand to mean that you're getting into OK so as to call it a slightly comical here and I and that is methyl group what I'm doing and that simply redrawing when the meet at that hour Soriano roaming across this double bond is that methyl groups taking on the other side 1 of the bromine heads from 1 phase and the other roaming ads from the opposite face and I'm going to get any Montana out of this plus the and this was a very particular meso type substrate with a mirror image plane of cemeteries for itself on so this is a notice how now that it's cycling on you can really see that in the relationship between the 2 broke means that added across double bond but let's take another example of arms of edition in this case just like the 1st example the 2 ends of the al-Qaeda not identically substituted this molecule has no sterigenics centers in it that means there is knowing intimate and this particular case but what you have here is you have to worry about the fact that the bromine Quaternary center can be either up or down another was that the brominated partners center can either be understating faces this methyl groups warning of underwent abbreviated methyl group within each really emphasize the fact it is just as likely that you'll get a product in this case on which this bromine is on the opposite phase and that is not an amenity that's a dire scarier and in my class who may not be abbreviated divested farmers by writing plus you have to literally draw them out to the other on the other product that you get it doesn't matter whether audience of bromine upper down what matters is that the hash so the other product that you have as the bromine and the methyl group on opposite faces of the ring so that a dice .period it's not an antimatter there's no sterigenics under here but look at this center over here next to them at all it it's it's got identical substitution on top and bottom so there's not for different substituent on this on that died of carbon there so and it is reminded that this is a dire scared and that's why you have to draw that you can't let Plessey so don't write plus D for that try to the winding up this issue up above here well up above the endangered are not 1 of the bromine is on the same faces the methyl solid enough to worry about that OK so look for the formation of a new tumors and I experience yet to watch and I asked those questions and Sabine homework help you practice that and we have some questions on the problems that help you think about stereo chemistry exterior chemistry suddenly becomes a big issue here in this chapter on because so many of these reactions of double ones creating new sterigenics centers OK let's talk about this so this former encased in a little more detail so we can talk about the stereo chemical implications of halogen nations but there was little that the mechanism and I'm going to once again tried to draw money out the in a way where I can really see that there's too faces a top-to-bottom face to the Al-Qaeda some trying to draw the singer John and use my Apple groups sticking out is my abbreviation for Apple it and my bromine comes in and in this case I'll show on I'm going to start off by 1st showing you the case where the bromine ads from the top face so there's bromine my molecular bromine use hero person I'm going to take the electrons in the southeast and I'm going to do something almost like an Anderson to reaction but remember there's a 3rd area we have to draw and so for some popping out of the misleading but remember there's these electrons on bromine all those long pairs conceded were forming a couple can we don't have to be that will just come right in an attack so that you don't end up with a problem that is that the era of it's the bizarre it's hard for you to remember because 3rd error if you agree is nothing like you've ever seen in chapters 9 ages 7 and then you're going to have to practice that OK so what you had in this case some showing edition of ammonium mined from the top face but that double bond and from the same side on which the other four-member and that the Uzzell group was on solid at this site to promote the mind intermediate and I want to make sure get these things when the trade these things just right here so here's my br so that's my side with Ramon mind intermediate and I would that on this no priest had drawn attack from the bottom faces this is going to be sort of weird so that there is the AA-minus floating around still and it's going to attack that ammonium ions remember what we said to beyond minus attacks from the most SUVs on the most substituted carbon you get during opening on the most substituted carbon so watch this analytical rigor the tertiary center and is running on the bottom side in the book attached that's not a very good air exercise doesn't look very good so whenever running on the bottom side attacks and here's why I was doing this in a different way and that's going to lead to this tie over here so the bromine at the at the tertiary center is now on the opposite phase of the Ethel group and the other product that will get out of this reaction on is going to arise from the addition of the building from the bottom face Eleni and tried to
redraw like 2 reactants here she can see how you get this of product there is no need to on the top face and if I had the bromine out from the bottom faces that often because the the double 1 to not equivalent faces 1 face of the double 1 as is on the same side as the and the other face of that going on the same side as they age that I do on the bottom so once again I'll drop the double bond attacking and then I have to remember to draw the lone pairs on bromine coming back in an attacking 1 of the 2 carbons so don't end up with a cargo there we go again that's the 1 that's going to be hard for you to remember and this will generate a cycle of ammonia mine intermediate and these are the same 2 reactants unjust and awarded draw everything with 1 structure this nugget of ammonium ion the bottom Fraser it is my bemoaning and with the where the bromine is now on the bottom face on the same side as were the ages I'm not going to forget positive charge bromine and I drove almighty and I encounter on floating around it's going to do anything to opening up more substituted center and that's going to lead to tenants find my heroes were so messed up this looks like some sort of bizarre roadmap I did not do a good job the think this industry and that gives the other guy history from action OK so why did we get to guys Germans we got guys terrorist because the often had 2 faces and the initial bromine command from the top place working out from the bottom phase and you have to take that into account there's 2 different faces on and 2 that are often not yet aware of that nite in every case but in this particular case becomes an issue OK so and again you will see a lot of reactions were you generate relatives stereo chemistry singing empty or you have to worry about absolute exterior chemistry because you generate a sterigenics centers and nothing short of practicing lots of problems will prepare you for that OK so we're not talked about 3 reactions so far we've we've talked about acid catalyze edition of HBO not as a callous but addition of yacht and HCl across double bonds we talked about acid catalyzed hydration the water across Bonjour alcohol we talked about edition of allergens bromine and chlorine B R 2 and sealed 2 they go through cycles of ammonia intermediates some initially of course reaction for this chapter that also involves the site of Colonia mind intermediate so it's going to start on the 1st of the showing of the way the product's look so here's a double bond have got bromine and that looks deceptively like the reaction I just showed you the differences I had a hydroxyl extolled either water or alcohol and then immediately that is just school meaning from my attention so I don't know what you see is what I see the medicine water like that but that's what I see in its blinking on and off movies I immediately know it's not going to be like that of the reaction was to bring crust and so yes you do get a carbon running behind but the more substituted carbon it's not a halogen anymore it's whatever your soul and was this water you know it's there and if you ran the reaction of high-quality math and all the other known with toxic so you have to look for that that other water well to look to see if there a hydroxyl kept us all included not just generated hysteria Janik center so I'm going to get the other Amantino out of this with hydroxyl is going down on and I'm not going to draw that possibly reckless OK so we also have to worry about this issue of relative Steering Committee here's another 1 of the sites like substrates and so when I had this time chlorine C. Allen OH across a double bond they end up wanting to each other this is another 1 of these cases where you have to pay attention to descending relationships the empty addition cannot describe anti-gun here so we remember that while the water is just the combined and that I would never use them so I get this the edition so the other product to get out of this of course have generated to sterigenics enters the other product is also entered the Indian Tampa which serves as a mirror images have to be unity as well can be something different from what is now the books sometimes on rights reactions using the NBS and Bromo 6 Intermezzo so sometimes you'll see stuff like this In the book and BSE and water and you don't need to worry about why the book chooses to use that region sometimes but in this reaction it does the same thing as Bjork you don't need to worry about what here the structure of the NBS stands for Enbrel 6 amid the endless using traditional nomenclature the ends italics because it tells you which Adam the bromine is attached to I'm so that's if you're interested in what NBS is this is the structure are we might see this later I I think in Chapter 15 only talk about radicals and radical chemistry but for now you don't really need to know the structure because when I show a mechanism I really want to learn the mechanism for br to not just for and and OK so it's walked through the mechanism for this for this reaction these products worry about hydroxy group 1 carbon atom away from halogen musical Halo hydrants so this is called Halo hydrants and this is when you mix allergens like bromine chlorine by using water as resolved so these these products OH in your Norwegian coring recalled people like because that's what the mechanism that's going to involve 1 of these the ammonia lines of credit and you guys by the end of this chapter yet in the experts with these with br ammonia mine and quarantine my information that kind of again and trying to draw this out he said the concede that there's 2 different faces here and so here's mine is my bromine my molecular bromine it's bouncing around my reaction mixture keeps colliding and eventually 1 of the collisions leads to successful bond forming reaction where this double 1 now attacks the bromine and displaces the leading group and and as I mentioned before the hero tree you're going to be inclined to reject this is 3rd year as that bromine gets closer and closer as I left these electrons away from the from the carbon atom here on the the the bromine periods will come back in an attack and I could just as easily have drawn this week with 0 going on to the other ,comma but the point here is making a bond to each of the carbon so if you wanted to draw this mechanism with a lone pair attacking this carbon instead that when you get the same product but again that's what I'm thinking about as they do all this is she it's going to start to form a tertiary care will catch on in this case secondary coverage and on but again I would count to correct if you're very narrow attacked the carbon it's less substitute because that gives the same product the same next intermediate OK so let's try our very exciting man Maryland 2 monster bromine that's why it's called of ammonium ions this 1 just happens to be a strange three-member green at the end here's here's where it matters that we use water as a solvent you that this cycle from owning any sum online is floating around unadjusted draw that the AA-minus floating where it is kind of lost the floating around looking for something to do but of course since we chose to use water as the solvent there is water everywhere so let me draw 1 of those water molecules everywhere right look at that Of course since water a solid there happens there will always be a water molecule which dangling right below In before using water as the solvent so as soon as reformers this summer so I could have only a minor it is much more likely that 1 of your many many water molecules will attack that is beyond minus that's often outer space the floating away the Soviet attack just like before at the more substituted position Ramon E. alliance attended a tactical more substituted position probe made up oxides which Iraq Sony mines and 3 brings get attacked the more substituted position so this is what leads to now it waters down near the bottom I'm trying to draw a line in this kind of parental lies and of course the water still has its Proton there's no hydroxide an iron in the reaction will you'll see momentarily is that we've got we're going to generate acid this reaction a good show bromide finally come into play that something will pull the proton their most inclined to draw a minus in this case Reuters br -minus if you choose if he chose to symbolize that the permit with the generic symbol a minus I would accept that buckets and now be AA-minus can float around and come back again and finally come around to the pro making this so please my red Pentagon it's another convict the proton off on and that's what gives you the Bromo I product but you finally get you've created a new stage in its center so that Angelo also get an intimate there is my reminded but the halo hybrid product so you get the other intimate because it's just as likely that the bromine would've initially added from the bottom faces that out by the 2 faces of the same there's no release as far as Rome is concerned it will spend 50 per cent it's time attacking the top face and 50 % it's time attacking the bottom-placed and formation gives you energy and intermodal addition nucleophile heads on the opposite faces the bromine electrical that initially yet but we have to stop right there on and when we come back here going to finish up with that 5th reaction CFI reactions to talk about his character and hydro Mauritian oxidation was it's going to be their time on Monday


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