It states that, in hydrohalogenation of an unsymmetrical alkene, the hydrogen atom in the hydrogen halide forms a bond with the doubly bonded carbon atom in the alkene, bearing the greater number of hydrogen atoms. Explaining The Mechanism of Anti-Markovnikov's Addition Rule With an Example. Markovnikov rule, in organic chemistry, a generalization, formulated by Vladimir Vasilyevich Markovnikov in 1869, stating that in addition reactions to unsymmetrical alkenes, the electron-rich component of the reagent adds to the carbon atom with fewer hydrogen atoms bonded to it, while the electron-deficient component adds to the carbon atom with more hydrogen atoms bonded to it. It is one of the few reactions following free radical mechanism in organic chemistry in place of electrophilic addition as suggested by Markovnikov. Anti-Markovnikov reactions. Anti-Markovnikov Addition Definition . Markovnikov’s rule is an empirical rule used to predict regioselectivity of electrophilic addition reactions of alkenes and alkynes. the acid catalysed hydration of alkenes (Markovnikov) and the hydroboration / oxidation of alkenes (anti-Markovnikov). It is one of the few reactions following free radical mechanism in organic chemistry in place of electrophilic addition as suggested by Markovnikov. Mechanisms that do not involve a carbocation intermediate may react through other mechanisms that have other regioselectivities not dictated by Markovnikov's rule, such as free radical addition.Such reactions are said to be anti-Markovnikov, since the halogen adds to the less substituted carbon, the opposite of a Markovnikov reaction. In summary, Anti Markovnikov's addition of HBr on an alkene gives a bromoalkane with the halogen attached to the least substituted carbon. Peroxide is an essential part. The most common type of Anti-Markovnikov addition mechanism is free radical addition. Anti Markovnikov addition is also an example of addition reaction of alkenes which is an exception to the Markovnikov’s rule. This reversal of orientation of product is peroxide effect and also known as Kharasch effect observed by M.S. Mayo in 1973. Markovnikov vs Anti Markovnikov Rule: Markovnikov Rule explains when the addition of protic acid with the formula of HX (where X= halogen) or H 2 O (considered as H-OH) to an alkene, hydrogen attaches to the double bonded carbon with the greater number of hydrogen atoms, while the halogen (X) attaches to the other carbon. The addition of hydrogen halide to an alkene in the presence of peroxide is opposite to Markovnikov rule. Anti-Markovnikov addition is an addition reaction between an electrophile compound HX and either an alkene or alkyne where the hydrogen atom of HX bonds to the carbon atom with the least number of hydrogen atoms in the initial alkene double bond or alkyne triple bond and the X bonds to the other carbon atom. Although Markovnikov's rule was developed for and is specifically applied to the addition of hydrogen halides to alkenes, many other additions are also described as Markovnikov or anti-Markovnikov depending on the regioselectivity of the addition reaction, e.g. This type of mechanism is applicable only for HBr - not HCl or HI - with either hydrogen peroxide (H 2 O 2) or benzoyl peroxide (C 14 H 10 O 4). In both the Markovkinov and Anti-Markovnikov's Rule, it is the stability of the carbocation and the radical that decides on the regiochemistry of the product. Kharasch and F.R. : Anti-Markovnikov Rule explains when HBr is added to an … Anti Markovnikov addition also referred to as Kharasch effect is an example of addition reaction of alkenes which is an exception to the Markovnikov’s rule. Anti markovnikovs rule When hydrogen halide is added to the unsymmetrical alkenes ,it results in the formation of alkyl halide provided that hydrogen attached to the carbon atom having less no. The Markownikoff or Markovnikov rule assigns the orientation of the electrophilic addition of hydrogen halides to asymmetrical alkenes or alkynes in which hydrogen itself attaches to the least‐substituted carbon atom in a double bond (or triple bond).