Organic Chemistry, "Change" - Part 12: Markovnikov's Rule

Greetings,

This post is about Markovnikov's Rule. This rule states that, for compounds consisting of Hydrogen, H cation adds first to the double -bonded carbon atom with the greater number of H atoms, bonded to it. This happens so that the more stable carbocation intermediate will form. The carbocation intermediate is more stable when the positive charge is located on the more substituted carbon atom, the other atom across the original double bond. It then follows that the second entity to add, often a halide ion, becomes bonded to the carbon atom with the lesser number of H atoms bonded to it.

Markovnikov's rule is useful because it allows the Chemist to predict the outcome of the reaction. The mechanism of acid-catalyzed hydration also follows Markovnikov's Rule, resulting in a hydroxide ion bonded to the carbon atom with the lesser number of H atoms. We say that an alcohol is formed, said alcohol product is a second or third degree compound. The degree of an organic compound is defined as the number of carbon atoms bonded to the C atom attached to the functional group; the hydroxyl group, for this example.

This post covered the basics of Markovnikov's Rule. Future posts will expand upon the basic rule, with more discussion and examples.

As always, thank you for reading!