Johannes Wislicenus German organic chemist, worked primarily in the field of chemical structure theory and stereochemistry. Date of Birth: 24.06.1835

1. Early Life and Education
2. Research on Lactic Acids
3. Development of Stereochemistry
4. Other Discoveries
5. Legacy

Early Life and Education

Johann Wislicenus was born on December 24, 1835, in Kleinpösna, near Leipzig, Germany. His father was a physician, and his mother was a daughter of a Leipzig wine merchant. Wislicenus showed an early interest in chemistry and attended the University of Zurich, where he studied under the chemist Carl Jacob Löwig. In 1856, he received his doctorate degree from the University of Zurich with a dissertation on the chemistry of urea.

Research on Lactic Acids

After completing his doctorate, Wislicenus began working as an assistant to the chemist Hermann Kolbe at the University of Marburg. In 1863, he moved to the University of Zurich to become a professor of chemistry. There, he began his research on lactic acids. He synthesized ordinary lactic acid and demonstrated its structure. In 1869, he established the identity of ordinary lactic acid and sarcolactic acid and proposed that their molecules have different spatial arrangements of atoms. These ideas provided the impetus for Jacobus Henricus van't Hoff's proposal of the stereochemical hypothesis in 1874.

Development of Stereochemistry

Wislicenus further developed van't Hoff's stereochemical hypothesis. He described the phenomenon of geometric isomerism using examples such as maleic and fumaric acids, crotonic and isocrotonic acids, and mesaconic and citraconic acids. In 1887, he proved that van't Hoff's theory could be used to establish all possible configurations of individual geometric isomers of unsaturated hydrocarbons. Wislicenus's research played a significant role in establishing stereochemical concepts in chemistry.

Other Discoveries

In addition to his work on lactic acids and stereochemistry, Wislicenus made several other important discoveries. He synthesized glutaric acid (1878), methyl-?-butyl ketone (1883), and others. He also discovered vinyl ether (1878) and vinylacetic acid (1899).

Legacy

Johann Wislicenus died on December 23, 1902, in Leipzig, Germany. He is remembered as one of the pioneers of organic chemistry and stereochemistry. His research laid the foundation for the understanding of the three-dimensional structure of molecules.