Competition of reactions in laboratory

 

When we talk about organic reactions like

Sn2

Sn1

E1

E2

E1cb  elimination via conjugate base

So we all have studied these reaction... Isn't it... 

We know that if we have good leaving group And strong nucleophile sn2 will happen

And if we have this that will happen it's true but not perfect

Actually when we do reaction in laboratory all sorts of things can happen if that are possible so we never get pure products we always get mixture of product but one of them is measure according to the condition we give for reaction then we purifying and get our major product.... 

So conditions are very important suppose you have an strong nucleophile and an alkyl hallide

Like this green color ball is chlorine it is Chloroprpoane

And you have some good nucleophile like oh-ve

So what you think you have good leaving group And strong nucleophile you will get sn2??? 

Ya you are right but sn1 will also happen.....the thing is major product is of sn2 but a little bit of sn1 product is also formed so you have to do purification to get major sn2 product. 

Let have more fun what Will happen if I put heat as well

Thn elimination also comes in possibility and any of reaction can happen , e1, e2, sn2

SO you see that reactions are competing

So we always get mixed product but one of them is measure according to the conditions we apply... 

If I would replace oh-ve by koH and cl by iodine and provide more heat  e2 will won the race but e1 comes 2nd and little bit of e1 product also get formed so we have to do distillation to get e2 product...... 

But what if you replace chlorine by flourine a poor leaving group and koh is there so what can happen base captures the proton first...formation of Carboanion thn fluorine leaves this goes via a  e1cb And you get Hoffman alkene but ya you also get a little bit of e1 product as well you have to purify the thing's..... 

So competition is everywhere even in reactions... It is funny right?????? 

Keep exploring guys...... 🙂🙂🙂