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Wittig Reaction

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Wittig Reaction
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This is the third (and final) 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. Index of Topics: 00:23 - Summary of Addition Reactions of Aldehydes & Ketones 03:39 - Addition of a Phosphonium Ylide (Wittig Reaction) 18:14 - Retrosynthetic Analysis 25:13 - Addition of Weak Nucleophiles 35:00 - Synthesis Example 39:53 - Structure and Physical Properties of Carboxylic Acid Derivatives 47:47 - Some Famous Type 2 Carbonyl Compounds
Eidgenössische Forschungsanstalt für Pflanzenbau bond mechanism phosphorus Radium Bohr media Phosphorous acid pumped case Säuren man electron Magnetometer Orlistat additions Magma Acetaldehyd Carcinoma in situ type rates nachwachsenden Rohstoffen steps rearrangement carbon chemische Reaktion source alcohols media end Hydration water van Säuren Computer animation yield coupling Gamma compounds remove chemical structures Dielectric spectroscopy basic oxygen Carboxylierung Pipette
Phosphorsäureester Index unsaturated phosphorus Phosphorous acid Alfred Lake electron Cycloheptatrien Eliminierungsreaktionen chemical element Double bond alkyl nachwachsenden Rohstoffen steps Karsthöhle chemische Reaktion firm end Alkane van Gamma compounds oxygen biosynthesis Gum arabic alkali species Polyurethane mechanism Radium Primärer Sektor plant Aldehydes case man Magnetometer Essenz <Lebensmittel> Common Erschöpfung Magma lithium sore areas type Essig nitrogen carbon Carbonyl Compounds proton charge Wasserstoff Computer animation function periodic table chemical structures Dehydration basic water waves
transition states Tactics unsaturated Bohr Mesomerie molecule electron additions Altbier color Aufdampfen nachwachsenden Rohstoffen steps Bock chemische Reaktion alcohols Titan Resin Gamma compounds oxygen sense sodium hydride bioactive mechanism activities Primärer Sektor current Bis (band) man fluoride Magnesium Magnetometer Magma Beta palladium Malt power nitrogen Bromide carbon hybrid proton Manganese Eiszapfen water conditions Computer animation function Genregulation chemical structures
acyl Ester Computer animation hydrides function Gamma Gases chemical structures Methylmalonyl-CoA-Mutase Perm (hairstyle) man
chain LSD Mesomerie Cocaine chloride Strength electron Aluminium hydride Löslichkeit Dipole Moment duration hydrides Gases properties stability Säuren artificial Resin Gamma polymer oxygen form Prostaglandine Stop bond Graukäse sodium hydride citric acid pumped Säuren man Magnetometer plant type Perfumer mixture nitrogen hydrogen bonding carbon Carbonyl Compounds hybrid Manganese charge water Wasserstoff Computer animation function formic acid chemical structures basic Farmer Carboxylierung Revenue
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ISO in this chapter we talked about reversible this is talented terms we talked about making higher rates we talked about making money acetaldehyde talked about trading acid tells we talked about making it means that we talked about making unit means of place sunrise all these reactions to them a lot of similarities what we know so far out tomorrow tradition actions in Quito's with very strong nuclear files this was generated in Chapter 20 Inc the reactions irreversible with mild nuclear vials reader nuclear files the reaction is reversible made within basic media historian basically or base catalyzed reaction or we can include files we need the project's 1st so we have a carbon yield we have a really good filed a generic nucleophile here many good vodka and attacks occurring renewal we kick electrons upon oxygen so far attack of the knowledge reaction I would get the new attacking 1st or the base attacking 1st and the 2nd step we have grown nation so ,comma mistake ICN exams and base catalyzed reactions to students from making the carbon oversee don't want to do that under Nasser college reaction of the carbon Hill is protonated 1st soporific the ,comma 1st announcing Callas reaction reversible error knows that we get our approach carbon which is now which is now more and more leptophilic so now we conclude valves can attack so we need to do this only a weak nuclear files and then in the 2nd step we have our attack by weakening the file such as water or alcohol water to make a hydrated alcohol maker acetone RAC exception is meaning unity formation mild acid catalysis nuclear file attacks 1st we saw that that was the last mechanism that we did last time excellence is a good summary of all that ,comma let's talk about the addition reactions about I think he tells which were were done with reversible additions and I will talk about some of the additional reactions on and added that the 1 reaction would talk about is the the reaction and I go I I understand you visited me doing again laughter the next couple weeks OK so I'm going to talk a little bit about that so of course on e-mail that irreversibly so we're back to irreversible reactions here talent taquitos but they undergo rearrangement of 2nd step to introduce the carbon-carbon bonds selectively in place of carbon you Our rights when we 1st study the reaction and you predict products and will go through how to make emitting region in Albania creating the actually reacts with the Kerviel so predict the product's 1st things 1st this only works for allies in key towns outside or a key tones only so don't try to do this reaction trying to evade with an but try do a very with the carboxyl Aghazadeh don't try to do a bit with in the UK on acid flights is only out I think he tells and here's what the overall reaction looks like as if we have a imagine yourself slicing despondent have measures of slicing and then you switch partners the phosphorus always gets the money drivers will work clearly hear the phosphorus always gets oxygen so we're slicing out and after slicing this and changing partners with the phosphors getting the oxygen so that enables you to draw the product really easily that's certainly not how the mechanism works we do not have bonds in half like that and then we and then reattach them doesn't work that way but that's how you can predict product and product will be trifled being offside so this is an stabilized severe take on this is a stabilized a Akira and so but still very agent L interfering to do the same thing so you can get serious about misuse and or a trance 1 of them is going to be a major and I I will say anymore anything more about that this is 1 of the things you'd need be looking at it in your experience and we also get trifle fasting alright so that's the reaction of this is more of a stabilized again this is this is a stabilizing Medicare this is and this is the answer is I'm stabilized is the stabilized so excited about 1st of all how we make both types I'm so preparation they degree agents or a possible an e-mail is another name for these so 1st of all in order to see head of her parodies of unwanted draw the resident structures for very in O'Connor help you see how we make this so we're a break the pipe bond going to move it on to the more remove the electors onto carbon and so I when it would look like in we draw the present structure it looks like that and that's really where gets its name from so is so ill and analysis this election which means that you have a lot of positive charge next to a negative and both ends with an architect so that's 2nd residence structure that I just drew on is actually number 1 gives you an idea of how you make this compound and to it also gives you more of an idea of how the hell you actually have to work with the mechanism for this reaction so to prepare this particular on fossil any in Illinois you take trifle personnel killed the light In this case it would be enough as interior action when you do
that as interior phosphorus is right then leaf nitrogen In the periodic table so when nitrogen species attack and Unison two-year positively charged nitrogen likewise you get a pass would positively charged of phosphorus here In the next step we need to remove this acidic hydrogen it's kind of a reach to call the city Kunduz and not very acidic PKA approximately 35 so in order to remove that proton we need a really strong base so the that's typically usefulness is a base called in Butare lithium the end just means nor also means the Bunal group that is not branched so it would look like this 1 2 3 4 hospitals tried it's an extremely strong waves OK then once you remove that acidic protons with your extremely strong base but you get the lake region so positive charge on phosphorus negative charge on the CHT RX-7 making 1 of the stabilized Illinois noise is stabilized minis you use you can use weaker bases and those of the kind you that you guys are going to be making a laugh because you're not allowed to use and deal lithium in an undergraduate Lasry actually not supposed to use and the lithium in the building at all but because it's Piura for and down we don't have that building is so old that it's not sprinklers so I know you guys are using bases of that nature but as a common basis to use to make alright so I might wanna try just just just to think about trying making news Mitiga reagent by the same method in Seaview cannot understand why we can use a weaker base with that but it's something to think about as you do in your lap alright so now all had a fast-moving e-mail is with within react with elder hides in key tones I'm going to show you are 2 ways here on a show you the way that I learned when I was a student and I will show you the new way that the teaching the booking it actually turns out that depending on what type of Vidic reaction really egregious you use you can have both of these mechanisms operating at the same time OK so it's a little bit more complicated even then you're doing in the last and certainly we draw unique and using the residents structure where we have the charge you can see that we have of electron rich carbon and we have electron deficient carbon on the carbon and so what's going to happen is that this is because the visitors situated itself so that the positive charge the negative charge a lot of the carbon here it's going to be near nearby the partial positive of the carbonyl and the negative charge of the oxygen there's going to be near the positively charged phosphorus little lined themselves up that way and then the Commons going to attack the Carbondale kick electrons 1 oxygen now if you do this step why I bet you can predict what the next reactions will be right with that oxygen spin attack phosphorus right all right so we have to species army fatigues and in brackets user to intermediates this 1 is called a bathing and this one's called an ox a contained so that is the debated made and very fleeting intermediate unlocks a fast attain on intermediate and spontaneously to decompose alright so now the soon so that that's the way that I learned this reaction we even have a special name for this baiting of EU text but now they don't do this reactionary ,comma combining these 2 steps into 1 so let me show you what they haven't sniffed I generally don't ask for this mechanism on exams I feel like you have enough mechanisms that you need to worry about UBS so it's going to situate itself just like we did there where the negative charge carbon is is adjacent to the positively charged carbon and possibly charge phosphorus is adjacent to the negatively charged oxygen and then it does us all in 1 step like that to go directly to the OPS fast it turns out depending on what type of agent that you have a lot of these 2 mechanisms actually can be can be found operating OK so depends on what we're Vidic region is and it isn't in this step right here whether you determine whether you have a is as E or EE teenager this so it's it's more complicated and then you're being presented in the laugh the so that's what happens here this guy's going to spontaneously decompose Strother the areas for that and we need to do is remove barriers around in a circle it doesn't matter where you go clockwise or counterclockwise you just want the 1st Arab going to but the phosphors oxygen plant to make a new bond between prosperous and and the other was going go like that and then you can drive added to products "quotation mark through keeping everything right where it as there's going to be a new double bond here and then there's going to be I double bond between the phosphorus and the oxygen so the overall result is a synthesis of pain synthesis of our teams from Quito Geraldo heights From a key to our elder hide and
if you're grouping reactions you may have a an index card that has ways to make out Keane's this can be added onto your ways to make our index card if you have or sheet of paper that has that effect so that the overall product their questions anybody Price that's the and that's that's how you make emitting region that saw the region reacts with the carbon we showed you how to draw the product by slicing and dicing and rearranging let's see how we would use them with the vinegar reaction retro synthetically if you're Devondale Kenia said in that direction saying to make this something using a vinegar reaction you want to be able to take it apart and see what will your relations with me and see whether it's going to work or not so potentially and that's a big potentially any of you getting made by then they're not all going to work with the is certainly a way that we can consider and the 1 thing nice and out of the lake is it's a really good way to make these compounds like this where the double bond is jetting off to the ring those are :colon Axel 2nd double bonds in their difficult to make by typical elimination of and that those guys are difficult to make Vidic is a great way to make an axle sick with double bond like that alright so it's provides in 7 following and mean that should be team right using admitted reactions using the that would provide the best deal alright soaring is we're going to take this apart Richardson said now what we do many at once science the Viguerie agent 1 side's the Carbondale I worried take apart to wait and see which way is the best OK so where foreigners born here and so and if we do we could do to different ways of informing on 2 different ways we can have the left-hand side of the carbon on the right-hand side the the Vedic reagent we could have a will call this strategy being we can have the the right hand side the the carbon the left side the if we did that With the quietness so this that and and I showed you how to make a very big so we could take this apart for a 3rd if we were going to make this many creation we would need the corresponding out till the alliance In this would be the alkyl here that we would use we'd have that and we have trifle Foster if we're going to go use this strategy strategy we would make this military agent from this out he alive In trifle past and what we wanted to do we what we wanted to use you wanted choose strategy that's going to give us the best meal when you think which strategy would give you the best deal ARB because yeah this is the primary Uncle all that is in essence reaction if we use a secondary that's pretty handed right secondary lambasted the 100 years ago and hydrogen on them sector the secondary opulent and travel policy New going to get a lot more elimination so this best strategy is going to be strategy so let's fix that should be a hydrogen the pace of wants the best we're going to be less easy to because we have a primary out of their there were the 1st step in making the Vedic isn't as interior action so firearms dealers the lawless elimination of in event a strategy so that we wanna ride out the synthesis of the forward direction we start off with their uphill lied step 1 tribal step steps to and futile affair and then we add our current and there's a problem can questions on that synthesis anybody so attempting to use synthesizers compound using elimination reaction is problematic so we have restored the these are 2 possibilities here for local Hill is that we can use with this start with the South Philly alive and we will make this direction here regularly in that direction and what kinds of usually with what what ends up happening is that you you can get some of the correct product but you also get some has to be separated so remember when you did your elimination action allowed would you get prodigy again that really did dehydration and the and we made the Gasunie collected the gas data where we got 3 products he had isolated right separate unit 2 seperate unfortunately because those would be very difficult to separate the case so but the starting with this 1 here you're major product would where the where the double bond is part of the it's more stable the have the al-Qaeda in the ring parts of the Vidic is a nice way to do that were much more cleanly true right in the last part of this chapter written to come revisit 1 2 0 1 4 editions but operate unsaturated curve renewals it's inspiring the outline the tells chapter were discontent with elements the tells and how those work alright so I what we say we said every every news regions that do not irreversible edition or any the once you product is a major problem that's because we want to attack is fostered and since all of the nuclear falls except recuperates Kubrick's do their own thing all the new involves attacked in 1 2 position faster if it's a irreversible reagent OK come back off again and that's where the like the 1 to part with you have things they can do reversible addition like the region's we done in this chapter then they can they will still more quickly attacked 1 2 but found they can also come back off again and eventually when they attacked 144 the 1 for product and it's the thermodynamic we most stable enough which end up isolating as you're on major part so here's an example here and so this
is a reagent that does reversible Kerviel edition so we will attack the Carbondale faster but some of the time it will attract 1 forwards attacks 1 4 and that's the product that you isolate His it's the thermodynamic Mohsen starting at the most stable products OK so maddeningly ion isn't it will learn more about those in Chapter 23 but for now were there for the courier product OK so we have are In meaning here were gonna deep-frozen I do need a positive charge on this nitrogen so go ahead and throw positrons of nitrogen notice all these reversible errors here and now we need to convert the inner lane ion Suu Kyi to to out so using the prorated mean we just made in the last hour electrons oxygen can come down there were going to grab a proton ashamed error pushing 2 different ways for this step because some students don't like it this way I show you know the way that you can use so now we have our we have renewal so that's like that and we have as for me as our side of it and if you don't like it that way there's another way you can draw this error pushing it might make more sense to you and what it would look like is this going to redraw that compound and in a duties to draw the resonant structure for the Illinois I'm so to drug-resistant you for the England I would push electrons down here and put electrons on carbon there so this is a resident structure shortly due resonance arrows in brackets In there you have it there you can see the negative charge on part right there and so that we can probably with that because from a from that resident structures this research is to resident structures of the same compound so you can really work from you resin structure does not matter to and I will give you the same color where since on that mechanism anybody would that RNC but him listed about here who likes the 1st Way I did in red OK likes the 2nd 1 Canada's superior OK so recall 1 additions faster as back reactants endure reversible addition reactivated tactic the current on their staff all we can do about irreversibly ad so they can come back off again since 1 win at some time the molecules are going to have enough energy to overcome the higher energy barrier and you 1 4 edition so you can see right here this is I 1 to this energy of activation for the 1 2 edition it is smaller so it's a faster reaction ETA for 1 2 edition summertime summertime when those molecules collide they're going to have the the energetic enough and is properly oriented to do 1 for edition so here's energy of activation 4 1 4 editions so higher energy to do 1 for additional higher energy of activation OK so once you go down here now we hear this lower energy transition state brings you to the 1 to product in years the energy diagram as we move to product here on this other of the one-story addition on the other hand so this would be Laura gene activation will goes here that's actually a higher energy intermediate and being on down here and that continues and this also goes to the higher energy part so time on the molecules have enough energy to go on overcome this larger energy barrier that goes down here all the way here and then goes to the more stable product now on which 1 of these reactions is more likely to reverse From here from here this 1 right because it from this to reverse it has to come up with how much energy it has to go along with a lot of energy going to go back here as always back here the peso on once this goes here it's much less likely to reverse because it's takes so much energy evaporation to reverse so we that the term that a thermodynamic well it's like it's fallen into well a kick it back out again and eventually the molecules are all going to fall into the well enough to Japan isolated event so to change its Tuesday most go back again is an icicle with way more energy than this guy go back again so that's the idea here more rights so less stable product here when the scroll up a little bit here less stable product more stable so over here on the right hand side Weiss energy of activation for the ones you products smaller wise that smaller but if we look at the hybrid for alpha-beta unsaturated ,comma the so that the hybrid here finally extra groups often just focus on the back from here with :colon like this and how you how can you be happening at the hiring by drawing the resident structures here you can come up with the hybrid so we have a lot of reading have personal negative charge on oxygen we're going to have a partial positive here again have partial positive here is the reason that the energy activation for the 1 2 product is smaller is that there's more on a partial positive charge on the cardinal there's more partial positive charge right more partial positive charge on carbon you so it's more electrical it's more a lecture frolicked in the car on that and is so it's going to be easier for nuclear files to attack at the current of carbon rather than those of the at the 1 for the position which would be the beta part right questions anybody who writes We will most probably the order while I was always say example for year I think we need to take that for often
already did it's in my notes here it's not here said this example of that so the devices since the the following 2 contracts from the given starting material any I need it sinks are really it's not very obvious here uses sector remember when you have and saturated ,comma we form the 1 to 1 1 4 so it turns out that 1 of these so so so if the if it seems we have a common illnesses the opposition is the beta position in the 1 for product we have a nucleophile are incorporated into the bay position so you want to get to meet the file here I'm over here Our nuclear files in is is is I actually all the carbon you so this is the 1 to product 1 2 edition this is 1 of of 4 conditions so the 191 for edition we have to use Sudoku breaks or things that do reversible cartwheeled yielded shipping wanted you want to additionally really powerful nuclear files so for the 1 2 edition what would be a file yet bring your original with right he's powerful nuclear all right so there's our starting material here step 1 will use I'm feeling an agreement today here Ethel magnesium bromide followed by water thank his assumed alcohol and what we still need when we need to do to get the product each to palladium about that so that's the 1 to product followed by reduction but on the other 1 is the 1 4 editions so for the 1 fluoridation we use a weakening nuclear files or recuperate still want steps to which Europe class by the the way since the since I haven't put up the podcast for nomenclature will have nomenclature on this exam Ordinance procrastinating having examined were to return to the bank so no nomenclature there questions on Chapter 21 anybody yes that's all the podcast nomenclature so when you have a carbon yielding the carbon it's adjacent to the Cardinals and then you count using the Greek letters as you go Alpha Beta Gamma Delta because yet more questions so let's say
this and will go back to your instrument chapel 22 so Chapter 22 England do the same thing we did in Chapter 21 but now we're talking about time to Cardinals play courses about exam while waiting for this to
say alright so products so
guess going remains we call them tied to curb are excellent let's review what we know about tied to Carbonell said we had the other group all that has long Paris Our so this is are generic so we draw identical pairs oxygen-rich structure we have asked court to the esters carboxyl gasses in implied hydride let's look at some physical
properties boiling point here 118 for carboxyl gasses the 52 furry corresponding I'll kill him alive massacre arson acid here like acid chloride 77 for Esther 21 that's not it's best not a mistake to 21 139 and to 70 alright in earnest the 5th solubility and will talk about these instruments here infinitely soluble four-CD gasses acid chloride reacts violently with water so we can't really measure it said water solubility right that's violently with water will talk about the product that you get when that reacts violently with water 5 many yesterday with an ethical groups 8 . 6 0 grams in 100 miles of water then 100 grams of Wash ended up 197 . 5 grams In 100 grams of water In hydride reacts with water so we can't really measure solubility there and um carboxyl aghast long chain ,comma so I guess it notice 8 there we have on 0 . 0 1 5 GM in 100 grams or what all right so as we're in increasingly the chain currently in Iraq governmental elegant 9 carbons here but 1 common design greatly decreasing solubility by increasing boiling point is we're getting higher molecular weight right I should see what else why would it why wouldn't have comments on gas in the environment has employed boiling point this can hydrogen bombs itself divers OK Esther among itself no ceiling on Isiah molecular weight than the carboxyl aghast at the the beginning I read about the self-sustainable willing .period wisest 1 answer to enormous sum boiling point here why is that so much higher this actors dissonant farmers hire as strongly as hydrogen bonds as a carboxyl now so why is this so high it has an extremely large dipole moment that you can't really talk about that ,comma wasn't very large stifled that's why so high very unusual dipole moment here it will talk about wine just a 2nd chance very large dipole moment we mentioned it in Chapter 20 but let's look at that again alright so both covered so gasses information secondary for my bonds and therefore higher boiling points greater solubility other type 2 and so here's a dipole dipole attraction with stronger resonance structure here the gives us such a large dipole so I'm going to move over to the left ear draw the resin structure so this is for me and we have formic acid and analysts compare will put brackets around analysts compare that with the carboxyl gasses and will return the dipole here 3 . 7 3 device that's huge and Furyk formic acid in his mom .period 4 device OK so and so There really is is this guy on this is the 2nd residence structure he's a really large part of the by hybrid virtue reasons number 1 nitrogen Indian when going from this Western structure to this 1 nitrogen is donating its electrons and had we won we know about that based strength wherever we related based strength 2 1 resident stabilization is a nitrogen or oxygen a stronger base nitrogen by 4 right so other than reasons since nitrogen such a strong base in really wants to kick in its electrons are much more than oxygen so on kicking it's like France in moves electrons up on artisans we get a negative charge of oxygen their positive charge of nitrogen this can do the same thing but it's it's not as basic so it's not as likely to donate its electrons we still are forming this negative charge of oxygen on but that the partner in charge is not a happy 1 oxygen as it is on nitrogen right so all those reasons combined so we gotta remember and we did we his residence structure and in Chapter 21 we were doing with the aluminum hydride personality and we said that this is really important that structures really important OK so very similar to that tertiary except significantly lower boiling points despite the fact that they have higher molecular weights because they cannot form hydrogen bonds so if we compare the 2 misses to 21 again this is 1 6 2 6 so we really have to think is making this boiling points so high I'm it and that we had this enormous dipole in we have hydrogen bonds it when you can have the hydrogen bonding school but that's still pretty high is therefore no hydrogen questions the anybody something as Class 1 of why Sinclair news event that I didn't
expect something was tied to carbonyl compounds cocaine of us didn't do we have analysis pastors right know McCain Hester's Palestine Valium and right these are all tied to revenues Kathleen something that looks like any is not quite Nunavut is like a double on the Nevada tossing think we have an 800 but it's also it's like an airliner over the nitrogen right will prostaglandin a carboxyl aghast citric acid carboxyl gasses pastors these guys this is not like teach so these are using the perfume and artificial flavoring industry and this has been an all-white some of my students made this week Lawrence of flavors and scents OK .period well and we have 1 more Missouri on nomenclature CE podcasts getting explosive throwing 1 more thing here now we can't stop
right there talking about great