Johannes Wislicenus

Born June 24, 1835, in KleinEichstedt, near Halle; died Dec. 5, 1902, in Leipzig. German organic chemist; worked mainly in the field of the theory of chemical structure and stereochemistry. Professor of chemistry at the universities of Zurich (1864-70), Wurzburg (from 1872), and Leipzig (from 1885).

From 1863 to 1875, Wislicenus did research on lactic acids, synthesized ordinary lactic acid, and showed its structure. In 1869 he established for the first time the identity of ordinary lactic acid with sarcolactic acid, whose molecules have different spatial arrangements. These views served as a direct impulse to the introduction of a stereochemical hypothesis by J. H. van’t Hoff, which Wislicenus developed further. In 1887 he showed that the use of this hypothesis permits one to establish all possible configurations of individual geometrical isomers (stereoisomers) of unsaturated hydrocarbons. Wislicenus’ research provided strong scientific confirmation of stereochemical concepts. He synthesized glutaric acid (1878) and methyl-/3-butyl ketone (1883). He discovered a vinyl ether (1878) and a vinyl acetic acid (1899).