52nd International Chemistry Olympiad, Istanbul, TURKEY
Preparatory problems: THEORETICAL
Problem 4. Early Russian Organic Chemists and Markovnikov’s Rule
The last year was devoted to the 150th anniversary of the discovery of Markovnikov's rule, formulated by Vladimir V. Markovnikov in 1869. Markovnikov was a PhD student of the famous early Russian scientist Alexander Butlerov. In his PhD thesis in 1869, Markovnikov discovered the famous rule that exists in almost every textbook on organic chemistry. According to Markovnikov’s rule, when an unsymmetrical alkene or alkyne reacts with a hydrogen halide (hydrogen chloride, hydrogen bromide, or hydrogen iodide), the hydrogen atom of HX adds to the carbon atom having the highest number of hydrogen atoms. However, depending on the reagent or substrate, in some cases, opposite results could also be possible, and these kinds of reactions are called anti-Markovnikov addition. Although Markovnikov's rule was developed for and is specifically applied to the addition of hydrogen halides to alkenes or alkynes, many other additions are also described as Markovnikov or anti-Markovnikov depending on the regioselectivity of the addition reaction.
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