Markovnikov’s Rule

Markovnikov’s rule refers to the tendency of alkene addition reactions of HX to proceed such that the hydrogen (H) ends up bonded to the carbon bearing the fewest number of alkyl groups (“least substituted”), and the X ends up bonded to the carbon bearing the greatest number of alkyl groups (“most substituted”). An example of regioselectivity, it arises due to the greater stability of more-substituted carbocations.