Skip to main content
Library homepage
 

Text Color

Text Size

 

Margin Size

 

Font Type

Enable Dyslexic Font
Chemistry LibreTexts

Markovnikov’s Rule

( \newcommand{\kernel}{\mathrm{null}\,}\)

Markovnikov’s rule is an empirical rule used to predict regioselectivity of electrophilic addition reactions of alkenes and alkynes. 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. (Morrison and Boyd in the fifth edition of Organic Chemistry quotes the King James Bible as a metaphor to Markovnikov’s rule: Unto everyone that hath shall be given. In simpler language, the rich get richer.)

eg. 1:

markovnikovrule1.png

To afford the observed product, the net reaction is addition of the hydrogen atom in HBr to the doubly bonded carbon atom in the alkene, bearing the greater number of hydrogen atoms.

markovnikovrule2.png

eg. 2:

markovnikovrule3.png

To afford the observed major product, the net reaction is addition of the hydrogen atom in HCl to the doubly bonded carbon atom in the alkene, bearing the greater number of hydrogen atoms.

markovnikovrule4.png

Although originally stated in relation to hydrohalogenation of unsymmetrical alkenes, Markovnikov’s rule applies to some other electrophilic addition reactions of unsymmetrical alkenes (eg. 3) and to some electrophilic addition reactions of unsymmetrical alkynes (eg. 4).

eg. 3:

markovnikovrule5.png

eg. 4:

markovnikovrule6.png


This page titled Markovnikov’s Rule is shared under a All Rights Reserved (used with permission) license and was authored, remixed, and/or curated by Gamini Gunawardena via source content that was edited to the style and standards of the LibreTexts platform.

  • Was this article helpful?

Support Center

How can we help?