Term: Saytzeff rule
https://doi.org/10.1351/goldbook.S05481

Definition:
Dehydrohalogenation of secondary- and tertiary-alkyl halides proceeds by the preferential removal of the β-hydrogen from the carbon that has the smallest number of hydrogens. Originally formulated by A. Saytzeff (Zaitsev) to generalize the orientation in β-elimination reactions of alkyl halides, this rule has been extended and modified, as follows: When two or more olefins can be produced in an elimination reaction, the thermodynamically most stable alkene will predominate. Exceptions to the Saytzeff rule are exemplified by the Hofmann rule.

Related Terms:
1) markownikoff rule (http://doi.org/10.1351/goldbook.M03707).
2) elimination (http://doi.org/10.1351/goldbook.E02038).
3) stable (http://doi.org/10.1351/goldbook.S05900).
4) hofmann rule (http://doi.org/10.1351/goldbook.H02830).
5) olefins (http://doi.org/10.1351/goldbook.O04281).

Source: PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1162 (https://doi.org/10.1351/pac199466051077)

Citation: 'Saytzeff rule' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.S05481

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