AB Tutorial

Added: 2026-05-12

[00:00:00]next we'll start alkenes preparation from alkenes we'll start it that is professional halwa pins from alkenes so when you take alkenes now previously I said you the reaction was nothing but it was a free-radical substitution reaction here it will undergo an electrophilic addition reactions against Allah so here if I take ch2 double bond CH 2 plus we can say HB depends on that so you will be getting ch3 ch2 BR you will be good so here what you find is that the alkene I have taken is nothing but a symmetrical alkene applicants symmetrical means that is the double bond is is in between that is the two carbon atoms that means on either side of the double bond equal number of an item if it is present and is said to be as symmetrical now if I take an symmetrical alkene CH 3 CH double bond CH 2 plus h BR if I take it then we have studied already according to my electronic of solute in class lemon I am sorry according to the mechanical rule the electronegative group this is your Pia it's being added to that particular carbon which has the least number of pattern ultimate attitude so it will be our India stage 3 that's HBR single bond CH 3 okay so we have studied this particular one this is according to my Panther soo now if if I if I take here after outside which is known as antimatter part of this route or we can also say this say harsh effect there is any peroxide again sir that that is our any peroxide offending it so what will happen is that instead of adding to the first second term ready to be added to this particular ch3 ch2 ch2 PRS versus what I said you it is antimatter nakatsu we know you know these things so here you can tell course that is free radical addition reaction can't oppose already this this mechanism we have done it in class 11 we have seen in plus 11 you can go through your class seven to look so that you can talk to know how the reaction is being carried out that is the free radical addition reactions and this is your free radical that means your electrophilic that is nothing but addition reactions we can say that this particular one so this is a curve so this is the Fourier and amaya panicles rule we have said this particular now here I'll give you option to you you will find out the answer that why do we do the reaction hbr why not with that CL why not with a child we do it why the reaction is done with edge whether it's a homework for you this is a question I am giving to you you find out the hard sell and you let me know that why the reaction is Marconi comparative mechanical we do that gia not Alexia HIV cancer now if I want that is I him smell undergoes substitution reactions then what I have to do is that I have been heated this particular for example suppose CH 3 CH double bond CH 2 when it reacts with HB R we can say that so when it reacts with h VI now I wanted it undergoes it should undergo substitution reaction then I have to take the temperature at 7-7 Kelvin because when I will be heating at a high temperature what happens is that the it will be more the will get the major product it will be more and hence the reaction also will be irreversible in nature all right listen carefully the reaction will be irreversible in nature because this particular one alkenes undergoes addition reaction does not undergo situation rich when you heat it the more happens is that this particular carbon atom now this is and I eat this particular carbon atom from here and an item is being released or rather I should say hydrogen atom is being substituted by the electronegative but you can say the crew that least I should say here you will be getting the product ch2 be our single bond CH double bond CH 2 for it so here it will be getting in this way and if you take here that is nothing but here that is BR if I take H we are here i if I take it then that is one hydrogen you'll be getting it but I have to do this reaction with BR to listen we do this reaction BR 2 then what will be getting is that from here X is really is that H react should we have to fall it should be hot we can say that so here what we managed to do that here in case of alkenes if you want a substituted product then you require the temperature 773 will be at a high temperature substitution reaction takes place at the already come because this is on us you're nothing but from protein and remove the hydrogen minute remove an item from protein then this is an S Li this particular hell is collect so I get it that is nothing but and Ally bromide negativity so here in this case the solution and be done but only at a high temperature high temperature the reaction becomes irreversible if you do it at low temperature the reaction is reversible so the yield will be low but in high temperature the reaction is irreversible I have to get a major product we can see that now in this way we can also do another reaction that is said to be has NBS reaction because of that so what we do is here CS please CH double bond CH 2 we can say plus that is we will take suck see me my n-bromosuccinimide so what is succeeding as a ch2 COOH so instead of H what I am going to do is that I am going to take and be ah this is known as n ro mo sucks see new mind we can say that in presence of this also is a nothing but a substitution reaction what is going to happen from the Alaia karma the substitute this higher atom is removed and because the product is this this is I don't have any space I'm reading it here that is ch to be a single bond CH double bond CH to look it from here hydras remove and Bri is being added into space now here will happen in place of what is that we are it is going to come so hence what I am going to get it here sage - sage - si oh here see PO NH this is nothing but known as C in E might so you get this product so this is we actually Skoda's NBS reaction this is also known as and bs reaction we can say that this particular one so in this way we can prepare the different types of that is alcoholics from alkenes