 Okay, this one in this right down like this question in this right down top right down the dehydration of The dehydration of primary alcohol dehydration for this question. I'm talking about the hydration of primary alcohol follows e2 elimination reaction e2 elimination So the most important thing here it is what we have e2 elimination so there is no carbocation formation So here rearrangement won't be there Okay, since it is primary alcohol, so it follows e2 elimination e2 elimination It's a one-step process no carbocation forms hence no rearrangement here How do we write down the product first of all protonation of this hydroxy group? CH3 and then CH2 now in the next step Conjugate base D- it takes H plus from this the alpha carbon It takes H plus from this this counts. Oh, sorry This bond pair comes over here and this goes out of the living Okay, so the product of this reaction is without any rearrangement is CH CH3 double bond see No, I am writing this here to make you understand All these things happen in one step So one thing is I made one mistake This hydrogen is here Carbon is high Okay, so here you must remember if it is primary alcohol then e2 elimination no Formation of carbocation and hence no rearrangement Here it is not possible Since it is primary alcohol One step process no carbocation On the plus side No, it is not forming actually This goes out One day the alcohol follow the two elimination Okay See we can also use P-O-C-L-3 for this purpose Phosphorus, oxyneuronide we can use for this purpose The reagent is P-O-C-L-3 with pyridine What is the formula of pyridine? Around zero degrees else is the reaction time Okay, so if the product is reaction is this C-S-3-C-H C-S-3-O-H And when the reaction takes place with P-O-C-L-3 Pyridine Around zero degrees else is the products of the reaction is C-S-3-C-H level bond C-S-3 C-S-3-C-H That is zero degrees else is C-S-3-Pyridine C-S-3-C-H C-S-3-C-H Actually the reaction is P-O-C-L-3 C-S-3-C-H So that becomes N-Tach Which No sir like This bonds have pyridine with night What is the purpose of this pyridine? It extracts H-plus from this No sir No this is different reaction It's not like Different reactions Where you think P-O-C-L-3 is pyridine See this P-O This one This one is a good living room It's a good living room That's why it goes out easily from this So is it better than cleaning or growing? Yeah you can say It's a better living room That's why we convert this The purpose of this pyridine To convert this into this P-O-C-L-2 So that it can go out when N-plus comes out from this It's a good living room So basically Sir how do we get the money Living room is nothing but No the negative charge Whether it is stable on the atom Okay so if it goes out You see P-O-C-L-3 is there So negative charge on oxygen is more stable Then C-L-P-R-3 That's how we get it Now all these loops actually matter The entire group is going out So this is a living room This entire group is a living room That will be in the solution H-plus will be in the solution The purpose of pyridine It is behaving as a base This step is an acid base reaction It donates lone pair Takes H-plus from this So apart from concentrated S-to-S-4 We can also use this reagent At zero degree Celsius For this reaction Okay next slide down Sir why do you have to know that it is an exo-permic reaction What is the reaction exo-permic? So like why do you have to do it at zero degrees It is exo-permic reaction Because a strong bond is Sigma bond is getting break And weak bond, pi bond is forming So overall energy releases in this process Simple for cooling and upside down So that is heating No, no, no it is not Like this Cooling is written on the reaction On cooling Right on the next Reaction By the halogenation of Visinol dihalyte By the halogenation of Visinol dihalyte Right on The reagent used for this purpose First one we can use Na-i in acetone Na-i in acetone And the second one is zinc with An acid CS3-COH Ethanol also we can use Ethanol with zinc No like we can use the first one is Na-i With Acetone CS3-COH Or we can also use zinc With CS3-COH Or C2H5 Okay Right on this reaction follows E2 mechanism E2 mechanism So this reaction Visinol dihalyte is this We have halogen present At the adjacent carbon act This is Visinol dihalyte And when you heat this with Acetone C-COH It forms IBR, NaBR And C-COH So you use this with ZN With an acid CS3-COH It forms Again the same product With ZN-BR2 So what is the mechanism Mechanism is not triggered I will tell you how to you know Memorize this reaction So why won't you work with Seminaral dihalytes that Two halogen atom present in the same carbon act So this is not helpful Because that carbon halogen bond becomes Highly weak In presence of free electron again Metal gives electron That becomes weak And hence the two carbon halogen bond Gets break Here what happens It goes out this bond And this goes out So it is going out from two different carbon act When it is on the same carbon act For that also you can put the method We will see that method also Sir over here can be two halogen atom Yes Yes Then the product will be So this will be two halogen atom No no no One will go with IOD Other one will go with This thing In ZN-CL Then we have two halogen atom For this purpose we generally take Same halogen atom Okay Write down next plan to this Write down we can also use We can also use The other metals like Other electropositive metals We can also use the other electropositive metals Like any calcium Or magnesium for this purpose Any calcium or magnesium These metals instead of zinc We can use these metals Read out the product in this reaction The first one is Reaction first one product Sir we just get a double bond Between over H and H Like over H we go Yeah Okay What is the carbocation we get Methyl shift Methyl shift Methyl shift User Correct It's one to methyl shift Right You can Hydride shift to the other side What do you want to shift to the other side How do I No Tell me So why can't you Hydride shift to the bottom position Yeah No Here positive charge Yes How many are firing here Yeah Four Yeah Over here it's One two and two three Two How many we have here Three four Plus two You can see this is turning Okay So for methyl shift Three minus three Shift doesn't have to be methyl Because we're exchanging like one Anything and chip Because it's high loss that we always make It doesn't have to be ethyl If you have ethyl suppose here Then we'll shift Shift to methyl Sorry methyl here Because this ethyl Stabilize this because of high effect So what if I had like a Doh decal If I had one In that case There will be some ring formation Large compound So that in general We cannot see that No matter how big it is We can always shift Purpose is to get more stable Right, how do we check this We'll check alpha here So whatever you are feeling just shift So why would it form a ring Large ring of large compound So it's tendency to form A ring because any large compound Polymers if you have White has some helical structure Must have seen the structure of proteins Very complex because it goes like this It was very large The size is way right And there are some positive negative charge present Here it is not the case But there we have oxygen nitrogen present That develops some charge into this Because of that some attraction is there Big variable attraction and it forms a helical ring So when you have a large compound It has tendency to form a ring Because in the ring form it's more stable So whether it's methyl ethyl and you shifted methyl Then ethyl if we had It had less alpha hydrogen What else you compared to if we had Shifted the ethyl itself So because it would have CH2 in between No then we'll shift ethyl The purpose is to get more stable It should be safe Okay so This is the more stable carbocation And then finally what happens One H plus goes out So the number of product that we get here Is one possible product is this The other product is Any other product possible These are the three products possible The most stable one is The positive one The major product is this Then this We'll take hydrogen from the start button Here we have hydrogen We can take hydrogen from this carbon also Or we can remove hydrogen from this carbon These three products possible Next step may the base will take H plus From the adjacent carbon atom This H plus goes out, double bound here This H plus goes out, double bound here This H plus goes out Three products possible Okay now in this one Right and then H plus goes out from this And we get a ring This is stable This is stable for dancing This is nice It should be two more products One more product possible So it's good start Because it makes it so stable It wants to keep the positive Doesn't make that stable This carbocation is stable But it's not more stable It's more convert into another form It's more stable than these two guys No but in these two we cannot compare These two we can compare You know the charge is specific This is different one You cannot compare Horses Horses Horses In these two This one is more stable We can embed this one Okay now tell me one thing If suppose we'll expand the ring here Then what is the product we get Ring expansion What is the product Ring expansion What is the product we get What is not supposed to show No I'm just asking Question is suppose I'll give you this question Ask you Tell me the product of this Ring expansion Wrong Okay See how do we do ring expansion We'll number the carbon as the first Starting from this carbon one Two Three Four carbon So we'll draw four memory Properly Now here one And Any one of this one we can break Either this one or this one Suppose I am making this one And I am going to the first carbon So one attached with Four Which one have the positive charge Two Second carbon So here we have the positive charge And first carbon has First carbon has Two methylene One and two Okay And then what we can do One two Methyl shift not hydrolyzed shift One two methyl shift So one of this methyl shift Over here We'll get this one And finally H plus comes out The possible product here This one Or This one Or This won't happen But if ring expansion will break Sometimes they may ask Write down the steps involved In the conversion of this Suppose they leave the product like this Write down the steps involved So if the question is Write down the product in this Then we will write this one Okay not this one In this one which one is the most stable First one First one Okay Write down One more note I forgot to give you this One more thing I forgot Suppose we have a reaction CS3 CS2 OH Okay And this reaction is taking place In presence of a compound CS3 OH CS3 O minus And CS3 OH What is the product we get into this one I have to have done this What is the product we get CS2 double bond CS2 CS2 double bond CS2 right This When the temperature is less than 140 or 150 Right Then what happens the product of this reaction CS3 CS2 O CS2 O CS2 We get ether Apart from alkene So that will also At this temperature Here the temperature is more than 170 degree Celsius So you have to memorize The temperature also So what happens between Both products So below 140 Below 140 You have ether In this case actually This is behaving as a nucleophile On phase So this attacks on to this Carbon atom So what is the definition of If you do the space You may be able to So what's the difference then No, do a space a tendency To lose electron Except electron Lose electron Lose electron is base Nucleophile is where The negative charge is more Stable except to be A better nucleophile Right, so it is Other way See if you have this CS3 O minus If it is a better Nucleophile this will attack Easily Yeah So depends upon the Stability of charge you can say Whether it is a better nucleophile Okay So I mean My question is Is a nucleophile No But the definition is Base is tendency to lose electron And when This negative charge is less Stable Than any electron Deficient cycle So tendency for this to attack Is nucleophilicity Base may behave as a nucleophile But whether the better base Or good base is a good nucleophile That we cannot see So how do you define a good base Good base is what tendency to Lose load pair of electron And good nucleophile is what But the electron density is more And it attacks on to the electron Lose load pair is base Tendency for this molecule or ion To attack on to any electron Deficient cycle is the Nucleophilicity of that particular So sir base is good Whether or not it attacks on an Electron deficient cycle Like it can lose electrons anywhere It depends It depends on the condition It depends on the condition It depends on the condition It depends on the condition Bronsted acid has Bronsted base Loose acid has Loose base We are talking about Loose base Don't pair that combination So tendency to lose PoH minus is again a basic nature We are talking about in terms of Loose definition Sir can a base be a good base By some definition Bad base by another No See Bronsted base We cannot be safe Bronsted base has Loose base Because the pressure is different Bronsted base tends to lose PoH minus Loose base is Talks about what? Loose pair It is completely different PoH minus So here you see When you have temperature less than 140 degrees Celsius We get Ether as the major product So this reaction is very important Temperature dependent reaction These two you get mixture of both Alchene plus Next you write down What is the Mechanism of the Ether How many things do you want? CS3 CS2 OX Right From this H plus This goes out as H2 Right here we have H plus Positive charge Then this CS3 PoH minus attacks So where is the active charge From this Solenoid This goes out And this PoH CS3 attack From this