1. A SEMINAR ON Markownikoff’s AND ANTI Markownikoff’s RULE
Rayat Shikshan Sanstha's
S.M. JOSHI COLLEGE, HADAPSAR, PUNE-28
A SEMINAR ON
Markownikoff’s
AND
ANTI Markownikoff’s RULE
Prof. MADHURI TUPE (Assistant Professor)
Department of Chemistry

2. Markownikoff’s Rule
“When a hydrogen halide reacts with an unsymmetrical alkene the hydrogen of the hydrogen halide attaches itself to the carbon of the alkene bearing the larger number of hydrogens and smaller number of carbons"

3. Addition reactions of unsymmetrical alkenes
Addition of HBr to propene CH3CH=CH2:
H–Br can add in two different ways
Two products are possible:
Contains more H atoms
CH3CH=CH2
CH3CH=CH2
H–Br
Br–H
CH3CH2–CH2Br
CH3CHBr–CH3
Minor product
Major product

4. It’s all controlled by carbocations
Secondary carbocation
Two C joined to C+
Primary carbocation
One C joined to C+
Major product
Minor product

5. Types of carbocation Least stable Primary carbocation
One carbon chains attached to C+
Secondary carbocation:
Two carbon chains attached to C+
Tertiary carbocation:
Three carbon chains attached to C+
Most
stable

6. Reasons for carbocation stability
Least
stable
Electron-donating ability of alkyl groups.
Each alkyl group pushes electrons towards C+ charge of carbocation.
Positive charge is spread over alkyl groups
The more alkyl groups attached to the C+
The more the positive charge is spread out
The greater the stability of the carbocation
Primary
Secondary
Most
stable
Tertiary

7. Markovnikov’s Rule With unsymmetrical alkene
In the addition of an acid to an alkene the hydrogen will go to the vinyl carbon that already has the greater number of hydrogens.

8. Anti Markovnikov’s Rule
In the addition of an acid to an alkene the hydrogen will go to the vinyl carbon that already has the lowest number of hydrogens.

9. 4- Addition of Sulfuric acid
(H-OSO3H)
heat
Addition of Sulfuric acid to alkenes also follows Markovnikov’s rule,
as the example
Propene
Isopropyl hydrogen sulfate
H2O
heat
2-Propanol

10. 5- Addition of Water : Hydration
Addition of HOH across the double bond is in accordance with Markovnikov’s rule, as the example

11. 6- Addition of HOX : Halohydrin Formation
The addition of the chloronium ion, Cl+ or bromonium ion, Br+ and
the hydroxide ion, OH-, follows the Markovnikov’s rule, as the example.

12. 7- Oxidation of alkenes syn hydroxylation
1) Oxidation of alkenes with Permanganate (Baeyer test)
syn hydroxylation
Examples:

13. trans-1,2-cyclohexanediol
2) Oxidation of alkenes with peroxy acid
Epoxide
anti hydroxylation
Examples:
2,3-butanediol
trans-1,2-cyclohexanediol

14. 8- Ozonolysis Oxidation of alkenes by ozone O3
The ozonolysis reaction can be summarized by the following equation:

15. Examples:

16. 9- Polymerization A) B)