Question

What is MarkovniKov rule? Write it's mechanism with examples too.

Answer 1

#What Is the

Markovnikov’s Rule

The Markovnikov’s rule predicts the outcome of addition reaction carried out on addition of protic acid HX to an asymmetric alkene, also called hydrohalogenation (under standard conditions). It was formulated by Vladimr Markovnikov in 1865 

#Explanation of

Markovnikov’s Rule Mechanism

with a Simple Example

When a protic acid HX (X = Cl, Br, I) is added to an asymmetrically substituted alkene, addition of acidic hydrogen takes place at the less substituted carbon atom of the double bond, while halide X is added to the more alkyl substituted carbon atom. In other words, hydrogen is added to the carbon atom with more number of hydrogen atoms attached to it and halide is added to the carbon atom with least number of hydrogen atoms 

#Markovnikov’s Rule Mechanism

The driving force behind the reaction is the formation of carbocation on addition of H to the alkene, in the first step of the reaction [3]. The most stable carbocation is formed when H is added to carbon having more number of hydrogen atoms already attached – due to factors like induction and hyperconjugation – which gives the major product with Br added to less hydrogen-rich carbon