The traditional term describing the preferential formation in a chemical reaction of one @E02069@ or @D01679@ over the other as a result of the influence of a @C01057@ feature present in the substrate, @R05190@, @C00876@ or environment.
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1086 [Terms] [Paper]
PAC, 1996, 68, 2193. (Basic terminology of stereochemistry (IUPAC Recommendations 1996)) on page 2200 [Terms] [Paper]