 Now write down the product in this reaction, product in this reaction, formation of carbocation is RDS of this reaction, RDS is the formation of carbocation, so we always try to get the most stable carbocation. Sir, but is it always only one carbocation possible because you take the OH from one carbocation? Yes, that is the first carbocation. Is there any rearrangement possible that you want to check? So over here you can put it on that or take the one and then the carbocation. How do we do that? So shift the hydrogen electrons just to shift. Okay. Yes, what happened? What happened? The OH is in the diagnostic. Okay. This one? Yeah. Yeah. OH is in the diagnostic. OH is in the diagnostic. Okay, so the product that you are getting is this? This one. Wait, only one product. Okay, guys. You see, this is H class. Sir, it's not too... Okay, this carbocation. This carbocation is stable? You can. How this carbocation is getting unstable? What is the effect there? Hypocontrugation. Hypocontrugation. How many alpha iron are there? Four. Four. We have one iron in here. Now what happens? We can do the rearrangement here. The rearrangement is possible. We said that whenever carbocation forms, we always try to get the more stable carbocation. Right. So what happens is hydrogen takes this bond pair of electron and shifts onto the adjacent carbon which has positive charges. Okay? So this bond pair of electron with this hydrogen, it takes these two electrons and then this H-myron will shift onto this carbon which has a positive charge. And it is only possible with the adjacent carbon hydroelipon. Okay? Here possible. Here also possible. So what we get here, you see? We have this. Do we have positive charge here? And this hydrogen comes over here. Now, this carbocation is more stable than this. Because how many alpha iron is here? Three plus three plus two. Eight alpha iron. So this carbocation is obviously more stable than this? Right. So reaction will not go like this? Right. We can do whatever we want. But the reaction goes like this. This will be rearranged. We will get more stable carbocation. And then from this, we will get alkene. So from any one of the carbon atom, we will take H-plus out. Okay? What is the final product we get here? So now where do we know where to put the W? How do we know where to put the W? In the final step? Tell me. Possible product is what? So you can make double bonds with all those colors. One product is this. Double monoblock. Another product is this. Which one is most stable here? The one on the right. This one. We are going more stable here. So make a product like this. Product both forms. But this one is more stable. So why is it more stable? Because more substituted alkene. The alkene is more substituted. Here. We have a post charge here. So you can remove H-plus from this carbon. Or from this carbon. This carbon also you can remove. But this one and this one both position are equal in position. So whether you remove H-plus from this one and this one you get the same product. So when you remove H-plus from this the bond pair comes over here and we get this double. This hydrogen you remove from here. Or when you remove this hydrogen this bond pair comes over here. So the number of hydrogen is given here. So the number of hydrogen is given here. So these are two hydrogen. Sir can you also say that carbon is actually a hydrogen? Yes we can say that. So does that logic match the hyper conjugation logic everywhere? No. That is why I am talking about So it is a more dominant thing, right? That's what I'm talking about. Okay, if hyper conjugation is the same then we'll talk about i, okay? So whenever we have a double con, it should be substituted as far as possible. It is always because this is a more stable problem through hyper conjugation. So should we write both or just write one? No, we'll write both but this one is me and this one is my friend. If they ask you what is the product of the reaction, then they only write the major one. Okay, how many product forms? Two product forms, major and minor. Okay, now you see this one, since this hydrogen is shipped onto this carbon atom, we call it as 1,2 hydride shift, hydride shift. Similarly, we can have methyl shift and phenyl shift also possible. Right, suppose in this one if I make one change here, instead of this carbon, this hydrogen, if you have CSP present here then, this methyl shift over here and in that case it is known as 1,2 methyl shift. If you have phenyl group here then 1,2 phenyl shift. Okay, same thing. Why we do this kind of shifting? To get more stable carbon atom. Okay, we always form more stable carbon atom. However, here the, you know, the, you know, if you write the product from this one, then you have a double bond this side also, the main, minor one, right? But that product is not forming in this reaction, not in this reaction. So, but you can only shift one carbon over here. You can't shift more than one carbon over here. So, like, let's say my hydride is on that one. Yeah, can I do 1,3 hydride shift? No, no, no, we cannot. Actually, why this kind of shifting happens? Because of this positive charge carbon, that adjacent carbon hydrogen bond gets polarized. This electron pair is mainly attracted to what's the positive charge. That's why this comes over here and in front of this. But over here, carbon hydrogen bond, there's no attraction. So, we should measure and find a problem. Or there's only one problem. Okay, now we're going to do a lot of stuff. Outside. Outside the right. Yeah. It's 367. 367. 367. Okay, see, in this reaction. Two and one. Two and one. Two and one. Right. We'll get this first. This is the first step. And then this H2O goes out. We'll get a carbocation like this. This is the positive charge, right? So, it will shift. The carbocation will shift. So, we'll get this. It's not a scam. I've done it. Everything is a scam. It's not an expansion. It's not possible. It's not an expansion. It's not an expansion. It's not possible. Okay. See, what happens actually. This cargo katana is 2 degree. And so, it's like this cargo katana. Anyone of us is aware. This one or this one. This will shift first of all on to this carbon atom. And this carbon atom is joined with this carbon atom. This we call it as ring expansion. Why this happens. There's a natural tendency of these kinds of things. Smaller ring is not that stable. Okay. The stability order of the ring is this 3-member, 4-member, and then 5-member ring. And we have 6-member ring. 7-member ring. This is the order of stability. Okay. Smaller member ring is lesser stable. Why? Because this carbon atom, what is the hybridization here? Hybridization? Hybridization. What is the hybridization here? SP3. So, what should be the bond angle? This should be the bond angle approximately, right? But what is the bond angle here? 60. 60. So, 109-60. We have 49 degree angle strain here. Because of its hybridization, this bond has tendency to expand and get this bond angle. But that is not happening because of this ring. Okay. So, we will have 49 degree of bond angle strain in this ring. Similarly, if it is 90, so 109-90, that is 90. So, like this, if you increase the carbon atom in the ring, the angle strain decreases. Angle strain decreases with stability. All these rings, smaller rings has natural tendency to convert into larger rings. 3 to 4, 4 to 5, 5 to 6. 7 to 6 also. 7-member ring is not that stable. So, we will also charge B on the other end. No, sir. Not shifting. Before shifting, sir. So, after the expansion, shouldn't it immediately come on? Yeah. No, sir. We will discuss it. The bond strain is the minimum with the pentagon. The angle strain should not be minimum with the pentagon. Because its angle is 108. So, 6-member ring, because of its orientation, it's a non-player, a commissioning ring. In a non-player molecule, it exists in chair form. Chair. Yeah. This is the stable one. Chair. No. It's not pain-gain. No, it's pain-gain. It's not pain-gain form. Right? So, because of this non-player structure, this is more stable structure. So, it is heptane also, like that? No, heptane is not stable. Heptane can form 6-member ring with a non-player. This one is non-player. Heptane can form 3-4. Heptane is also non-player. It converts into a 6-player ring. So, would pentane is clear? Pentane is clear. Okay. I am coming. So, this is the order of stability, correct? Yeah, this is the first thing we should know. Right? If the ring expansion takes place, okay, that you should know any ring. And if the carbon atom attached to the ring, if this carbon atom has one positive charge into this, then the ring expansion is possible. Means the charge must not be present on the ring. If the charge is present on the ring, then ring contraction will be there. Okay. In this case, ring contraction will be there. So, 4-member ring, 3-member ring and number number. But then again you will say 3-member ring palestable. Right? Let me see. See, whatever I am saying. Yes, dancing lessons. Whatever I am saying. See, whatever I am telling you. Let me finish this. Then you can ask him. Let me finish this first. So, condition of ring expansion is charge must not be present on the ring. It is present on the carbon atom which is attached to the ring. When ring expansion is possible. If charge is there on the ring, then ring contraction will be there. So, this will convert into this. Right? Here we don't apply this logic that 4-member ring is more stable. So, why it is converting into 3? Because this positive charge is established through dancing resonance. We know this is the most stable carbocation. That's why this conversion is possible. Only in 2 cases. 4 to 3 and then 7 to 6. 7th carbon atom to 6th carbon atom. So, this is it. Ring contraction will let it be. Now, here we have how do we expand the ring? Basically, what we do first of all, we number the carbon atom. We start from the positive charge carbon atom. 1, 2. You can number this as 3 or this as 3. Anyone? This is 3, 4 and 5. Starting from the positive charge carbon. We number the carbon atom. Now, since we have 5 carbon atom present total. So, we will simply close the eyes and we will draw a 5-member ring. Now, you number the carbon atom here. Now, you see this bond pair comes over here and this 5 attack on to the first one. So, it is 1. 1 is attached with 5. So, what we will write here? This is 1. So, this is 5. This is 2, 3 and 4. Correct? Now, this is methyl group. This is present on to the first carbon. So, first carbon big methyl group attached. Now, here we have one positive charge. So, here we should also have one positive charge. Now, which carbon atom is losing its electrons? 2 or 5? 2 or 5? This is coming over here. Second carbon is losing, right? So, second carbon will have one positive charge. This is the... Is it? Just... So, it can also be 3 if the pair goes from 2... What? What? No. Now, can that... I want to do that also. Is it clear? Ring expansion? So, this is how we do this ring expansion. Now, you see again if this hydrogen comes over here this secondary carbon atom converts into... Perfect. So, most stable carbocation is this. Eventually, you can. Okay. Most stable carbocation is this. Now, from this if you remove H plus from this carbon or this carbon on this carbon there are 2 possible products in this. There are 2 possible products. Why can't we do that? That also you can do. You will get the same thing. Anyone? Here and here. So, the answer for this question is this one. This one and this one. The second one is the major. The major one. Is it clear? From here ring expansion is over. 5-member ring is more stable than 4. This one is stable. Now, in this case what is the alpha hydrogen here? Can you tell me? 2 here plus 1. We have 3 alpha hydrogen. How many alpha hydrogen here? 3 plus 2 plus 2. More alpha hydrogen, more stability. So, this is the most stable carbocation. Now, from this H plus comes out from this carbon or this carbon these 2 carbons are equivalent carbons. So, either we get a double bond here or here. 2 front ends. More stability. Cycle expansion. We didn't run it. It is not done. I will just show the load. I will take after this. Do you have other science here? I don't need to teach the cyclic. I will take that. Which one? I will do it. Maybe he will come on. I will do it. What is alkane octane? It depends upon the molecules. See, we have this thing. Fuel. So, there we use all these. So, there we use all these. It depends upon the molecules. So, there we use all these. Cetane number we have. Octane number we have. That actually, you know, gives an idea of how efficient the fuel is. Anti-nocking agent we use. We will do that. These kind of questions. Sometimes they are asking me. 2-3 facts we have discussed. We will finish this. Anti-nocking agent. You understood this one. So, we will do it. Again. See, why? Wait, wait. See, can we do this? After this, we got this carbocation. These two are the same thing. We got this. And then this converts into this. By 1-2 hydride shift. This step is 1,2 hydride shift. To write down this ring, to draw this ring, we will number the carbon atom and then we will attack. Now, I will tell you why not. Here we have 1-2 hydride shift. So, we have that carbocation. You see, the carbocation is this. Can we do 1-2 hydride shift here? Not this ring expansion. So, if you shift this hydrogen here, again you will get 3-DD carbocation. Yes or no? 3-DD carbocation. So, why this is not happening? So, ring is 4 stable. So, ring is 4 stable. 5 stable. But this one is also 2-degree. It is converting into 3-degree. So, because after that, we will have to connect that. How many alpha iron we have here? 3, plus 1, 4. Yes. How many alpha iron we have here? So, same. 2 plus 2, 4 alpha iron. No, no. So, but it has more. It is plus charge and it has... Sir, it has 6. Sir, 2 plus 2, plus 2. Sir, 2 plus 2, plus 2. Yeah, it has... Yeah, 6. Sir, 2 plus 2, plus 2. Sir, 2 plus 2, plus 2. Right? 6. So, this is more alpha iron and less number of alpha iron. This one is more stable than this. But again, if you compare this carbocation and this carbocation, it is present on the larger member ring. So, angle is 10 is less here. So, this one is more stable than this. Sir, this angle is... Angle is... Does not have any angle. Sir, that... So, here we have less angle. So, also we have... Yes, sir. So, why doesn't it come? Because this carbocation is not more stable than this. It will not form. No, it will not form. No, it will not form. Sir, you can form. Sir, I am asking you. See, you can draw this. Again, you are getting it. Because after this, you will get dancing resonance and all. No, that's why you are getting it. Don't get it wrong. So, we always go towards the more stable carbocation. Right? So, this carbocation is more stable than this. After this, it will not form. See, in this also, if this hydrogen shifts over here, then we will get a carbocation here, right? In that case, alpha-hydrogen is what? Only 2. Which is less stable. That's why that shifting is not possible. So, whenever rearrangement is there, we always go towards the more stable carbocation. In the next step also, we are getting more stable carbocation. Then also, this is not possible.