Otto Wallach

Otto Wallach
Otto Wallach
Born	27 March, 1847 Königsberg, Prussia
Died	February 26 1931 (aged 83) Göttingen, Germany
Residence	Prussia, then German Empire
Nationality	Prussian, then German
Field	Organic chemistry
Institutions	University of Göttingen, University of Bonn
Alma mater	University of Göttingen
Academic advisor	August Wilhelm von Hofmann, Friedrich Wöhler, Friedrich Kekulé
Notable students	Walter Haworth
Known for	isoprene rule
Notable prizes	Nobel Prize for Chemistry (1910)
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Otto Wallach (27 March, 1847 at Königsberg - 26 February, 1931 at Göttingen) was a Jewish German chemist who won the Nobel Prize in 1910 for work on alicyclic compounds.

Biography

He was born at Königsberg as son of a prussian official. His father was transferred to Stettin (Szczecin) and later to Potsdam. Otto Wallach went to school, a Gymnasium, in Potsdam, where he got in contact with literature and the history of art, two subjects he was interested his whole life. At this time he also started private chemical experiments at the house of his parents. In 1867 he started studying chemistry at the University of Göttingen, where at this time Friedrich Wöhler was head of the organic chemistry. After one semester at the University of Berlin with August Wilhelm von Hofmann, Wallach received his Doctoral degree from the University of Göttingen in 1869, and worked as a Professor in the University of Bonn (1870-89) and the University of Göttingen (1889-1915).

Major works

During his work with Friedrich Kekulé in Bonn he started a systematic analysis of the terpenes present in essential oils. Up to this time the only few were isolated in pure form and the structural information were sparse. Melting point comparison and the measurement of mixtures was one of the methods to confirm identical substances. For this method the mostly liquid terpenes had to be transformed into crystalline compounds. With stepwise derivatisation especially additions to the double bond present in some of the terpenes he achieved the goal to obtain crystalline compounds. The investigation of the rearrangement reactions of cyclic unsaturated terpenes made it possible to optain the structure of a unknown terpene by following the rearangments to a known structure of a terpene. With these principal methods he opened the path to a systematical research on terpenes.

He was responsible for naming the terpene, pinene, and for undertaking the first systematic study of pinene^ . He also proposed that terpenes can be regarded as oligomers of isoprene; this is now known as the isoprene rule, and it assisted in the elucidation of the structures of many terpenes.

He wrote a book about the chemistry of Terpenes, "Terpene und Campher" (1909).

He is also known for the named "Wallach's rule" that racemic crystals tend to be denser than their chiral counterparts. (Wallach, O. (1895). Liebigs Ann. Chem. 286, 90-143.). This rule has been substantiated by crystallographic database analysis (Brock et al, 1991).

References

• Leopold Ruzicka (1932). "Third Pedler lecture. The life and work of Otto Wallach". J. Chem. Soc.: 1582. DOI:10.1039/JR9320001582. 

• Carolyn Pratt Brock, W. Bernd Schweizer, and Jack D. Dunitz (1991). "On the validity of Wallach's rule: on the density and stability of racemic crystals compared with their chiral counterparts". J. Am. Chem. Soc. 113 (26): 9811. DOI:10.1021/ja00026a015. 

External links

• Nobel Lecture Alicyclic Compunds from Nobelprize.org website
• Biography Biography from Nobelprize.org website
• Otto Wallach at the NNDB website.

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