The conversion of a substrate into a particular product, irrespective of reagents or mechanisms involved. For example, the transformation of aniline (C6H5NH2) into N-phenylacetamide (C6H5NHCOCH3) may be effected by use of acetyl chloride or acetic anhydride or ketene. A transformation is distinct from a reaction, the full description of which would state or imply all the reactants and all the products.
PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1173 (