A chemical reaction (or reaction
sequence) in which one or more new elements of
chirality are formed in a substrate molecule and which produces the stereoisomeric (enantiomeric
or diastereoisomeric) products in unequal amounts. Traditionally called
asymmetric synthesis.
Source:
PAC, 1996, 68, 2193
(Basic terminology of stereochemistry (IUPAC Recommendations 1996))
on page 2219