: a branch of chemistry that deals with the spatial arrangement of atoms and groups in molecules
: the spatial arrangement of atoms and groups in a compound and its relation to the properties of the compound
Term originated c. 1878 by Viktor Meyer (1848–97) for the study of stereoisomers (seeisomer). Louis Pasteur had shown in 1848 that tartaric acid has optical activity and that this depends on molecular asymmetry, and Jacobus H. van't Hoff and Joseph-Achille Le Bel (1847–1930) had independently explained in 1874 how a molecule with a carbon atom bonded to four different groups has two mirror-image forms. Stereochemistry deals with stereoisomers and with asymmetric synthesis. John Cornforth (b. 1917) and Vladimir Prelog (1906–98) shared a 1975 Nobel Prize for work on stereochemistry and stereoisomerism of alkaloids, enzymes, antibiotics, and other natural compounds.