Zaitsevterméket

Zaitsevterméket is a term used in organic chemistry to describe the major organic product formed in certain elimination reactions. This principle is most commonly associated with the E2 (bimolecular elimination) and E1 (unimolecular elimination) reaction mechanisms. The Zaitsev rule, named after the Russian chemist Alexander Zaitsev, states that in an elimination reaction, the alkene with the most substituted double bond (i.e., the one with the most alkyl groups attached to the doubly bonded carbons) will be the major product.

This rule is a consequence of the relative thermodynamic stability of alkenes. More substituted alkenes are generally more stable due to hyperconjugation, where the electron density from adjacent C-H sigma bonds overlaps with the pi system of the double bond. Therefore, reactions that proceed to thermodynamic equilibrium, or where the transition state leading to the more substituted alkene is lower in energy, will favor the Zaitsev product.

Conversely, the Hofmann product is the minor alkene product formed in elimination reactions, characterized by having the least substituted double bond. The formation of the Hofmann product is favored under specific conditions, such as when a bulky base is used in an E2 reaction, or in certain E1 reactions with sterically hindered substrates. Understanding the Zaitsev rule is crucial for predicting the regioselectivity of elimination reactions in organic synthesis.