Term: stereoselectivity
https://doi.org/10.1351/goldbook.S05991

Definition:
The preferential formation in a chemical reaction of one stereoisomer over another. When the stereoisomers are enantiomers, the phenomenon is called enantioselectivity and is quantitatively expressed by the enantiomeric excess; when they are diastereoisomers, it is called diastereoselectivity and is quantitatively expressed by the diastereoisomer excess.

Related Terms:
1) stereoisomers (http://doi.org/10.1351/goldbook.S05984).
2) enantioselectivity (http://doi.org/10.1351/goldbook.E02082).
3) diastereoisomers (http://doi.org/10.1351/goldbook.D01679).
4) enantiomeric excess (http://doi.org/10.1351/goldbook.E02070).
5) diastereoisomer excess (http://doi.org/10.1351/goldbook.D01675).

Source: PAC, 1996, 68, 2193. 'Basic terminology of stereochemistry (IUPAC Recommendations 1996)' on page 2219 (https://doi.org/10.1351/pac199668122193)

Citation: 'stereoselectivity' 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.S05991

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