Saytzeffin

Saytzeffin is a term used in organic chemistry to describe a rule that predicts the product of an elimination reaction. Specifically, it states that when a proton is removed from a carbon adjacent to a double or triple bond, the proton will be removed from the carbon that results in the formation of the most substituted alkene or alkyne. This means the double or triple bond will be formed with the fewest number of hydrogen atoms attached to the carbon atoms involved in the bond. The rule is often applied in reactions like dehydrohalogenation, where a hydrogen halide is removed from an alkyl halide to form an alkene.

The Saytzeffin rule is a generalization and is not universally true. Other factors can influence the regioselectivity of elimination reactions, including the nature of the base used, the reaction conditions (temperature, solvent), and steric hindrance. For instance, strong, bulky bases tend to favor the formation of the less substituted alkene, known as the Hofmann product, which is contrary to the Saytzeffin rule. In some cases, a mixture of both Saytzeffin and Hofmann products can be formed. Understanding these competing factors is crucial for predicting the outcome of elimination reactions. The Saytzeffin rule is named after Russian chemist Alexander Saytzeff.