Anti-Markovnikov Addition Defintiion

Markovnikovs Rule describes the nature of alkene addition reactions in organic chemistry. Russian chemist Vladimir Markovnikov formulated the rule in 1865 after noting the halogen atom preferred the more substituted carbon in a hydrohalogenation reaction with an asymmetric alkene. If a reaction follows the Markovnikov Rule: The nucleophile adds to the more substituted pi-bound carbon.Hydrogen adds to the less substituted carbon. Another way to think of it is that the hydrogen rich get richer, meaning that out of two pi-bound carbon atoms, the one that has the most hydrogen atoms will get another hydrogen in the reaction. But, some reactions dont follow this rule... Anti-Markovnikov Addition Definition Anti-Markovnikov addition is an addition reaction between an electrophile compound HX and either an alkene or alkyne where the hydrogen atom of HX bonds to the carbon atom with the least number of hydrogen atoms in the initial alkene double bond  or alkyne triple bond  and the X bonds to the other carbon atom. The anti part of Anti-Markovnikov addition is that the reaction fails to follow Markovnikovs Rule. It does not refer to anti in terms of stereochemistry! The image shows the Anti-Markovnikov addition of HX to a propene alkene. The H bonds to the CH1 end and the X bonds to the CH2 end of the former double bond. References Hughes, Peter (2006). Was Markovnikovs Rule an Inspired Guess?.  Journal of Chemical Education.  83  (8): 1152.McMurry, John. Section 7.8: Orientation of Electrophilic Ractions: Markovnikovs Rule.  Organic Chemistry  (8th ed.).W. Markownikoff (1870). Ueber die Abhà ¤ngigkeit der verschiedenen Vertretbarkeit des Radicalwasserstoffs in den isomeren Buttersà ¤uren.  Annalen der Pharmacie.  153  (1): 228–59.