View source for Otto Wallach

{{Short description|German chemist (1847–1931)}}
{{Use dmy dates|date=June 2015}}
{{Infobox scientist
| name              = Otto Wallach
| image             = Otto Wallach 1880s.jpg
| image_size        = 
| caption           = Wallach {{circa}} 1873
| birth_date        = {{Birth date|df=yes|1847|3|27}}
| birth_place       = [[Königsberg]], [[Kingdom of Prussia|Prussia]]
| nationality       = [[Kingdom of Prussia|Prussia]] / [[German Empire]]
| death_date        = {{death date and age| 1931|2|26|1847|3|27|df=y}}
| death_place       = [[Göttingen]], [[Weimar Republic|Germany]]
| field             = [[Organic chemistry]]
| work_institution  = [[University of Göttingen]], <br> [[University of Bonn]]
| alma_mater        = [[University of Göttingen]]
| doctoral_advisor  = [[Hans Hübner]]{{cn|date=August 2017}}
| doctoral_students = [[Walter Haworth]], [[Adolf Sieverts]] <!--[[Edgar Bright Wilson]]-->
| known_for         = [[Alicyclic compound]]s<br>[[Favorskii_rearrangement#Wallach_degradation|Wallach degradation]]<br>[[Wallach rearrangement]]<br>[[Racemic_mixture#Wallach's_rule|Wallach's rule]]<br>[[Leuckart–Wallach reaction]]
| prizes            = [[Davy Medal]] {{small|(1912)}}<br>{{no wrap|[[Nobel Prize for Chemistry]] <small>(1910)</small><br>[[Cothenius Medal awardees, 1864–1953|Cothenius Medal]] {{small|(1889)}}}}
}}
[[File:Grave of Otto Wallach at Stadtfriedhof Göttingen 2017 01.jpg|thumb|Otto Wallach's grave in Göttingen]]
'''Otto Wallach''' ({{IPA|de|ˈɔto ˈvalax|-|De-Otto Wallach.ogg}}; 27 March 1847 – 26 February 1931) was a [[German people|German]] [[chemist]] and recipient of the 1910 [[Nobel Prize in Chemistry]] for his work on [[alicyclic compound]]s.<ref>{{cite journal 
 | title = Third Pedler lecture. The life and work of Otto Wallach
 | author = Leopold Ruzicka
 | journal = [[J. Chem. Soc.]]
 | pages = 1582
 | year = 1932
 | doi = 10.1039/JR9320001582| author-link = Leopold Ruzicka
 }}</ref><ref>{{cite journal | last1 = Christmann | first1 = M | year = 2010 | title = Otto Wallach: Founder of Terpene Chemistry and Nobel Laureate 1910 | journal = Angewandte Chemie International Edition | volume = 49 | issue = 50| pages = 9580–9586 | doi = 10.1002/anie.201003155 | pmid=21110354 | bibcode = 2010ACIE...49.9580C }}</ref>

==Biography==
Wallach was born in [[Königsberg]], the son of a [[Prussia]]n civil servant. His father, Gerhard Wallach, descended from a [[Jewish]] family that had converted to [[Lutheranism]]. His mother, Otillie (Thoma),<ref name="Magill1990">{{cite book|author=Frank Northen Magill|title=1901–1937|url=https://books.google.com/books?id=jsfaAAAAMAAJ|year=1990|publisher=Salem Press|isbn=978-0-89356-562-6}}</ref> was an ethnic [[Germans|German]] of [[Protestant]] religion. Wallach's father was transferred to [[Stettin]] (Szczecin) and later to [[Potsdam]]. Otto Wallach went to school, a ''Gymnasium'', in Potsdam, where he learned about [[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 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,<ref name="Wallach1869">{{cite book|url=https://books.google.com/books?id=PJpTAAAAcAAJ|title=Über vom Toluol abgeleitete neue isomere Verbindungen: Inaug. Diss|author=Otto Wallach|publisher=E. A. Huth|year=1869}}</ref> and worked as a professor in the [[University of Bonn]] (1870–89) and the University of Göttingen (1889–1915). Two of his doctoral students were [[Adolf Sieverts]] and [[Walter Haworth]].<ref>{{Cite web|url=https://academictree.org/chemistry/peopleinfo.php?pid=51872|title=Chemistry Tree - Otto Wallach|website=academictree.org|access-date=2019-03-23}}</ref> Wallach died at [[Göttingen]]. In 1912, he was awarded the [[Davy Medal]].

He died on 26 February 1931, and was buried in the [[Göttingen]].

==Major works==
During his work with [[Friedrich August Kekulé von Stradonitz|Friedrich Kekulé]] in Bonn he started a systematic analysis of the [[terpene]]s present in [[essential oil]]s. Up to this time only a few had been isolated in pure form, and structural information was 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 of obtaining crystalline compounds. The investigation of the [[rearrangement reaction]]s of cyclic [[Saturated and unsaturated compounds|unsaturated]] terpenes made it possible to obtain the structure of an unknown terpene by following the rearrangement to a known structure of a terpene. With these principal methods he opened the path to systematic research on terpenes.

[[File:AlphaPinene.png|200px]]

He was responsible for naming [[terpene]] and [[pinene]], and for undertaking the first systematic study of pinene.<!--  He also proposed {{fact|date=December 2010}} that terpenes can be regarded as [[oligomer]]s of isoprene; this is now known as the [[Terpene#Structure and biosynthesis|isoprene rule]], and it assisted in the elucidation of the structures of many terpenes. Comment: An old obituary says that he was aware of the isoprene rule in 1885 or 1887, which is not easy to read out of the original mentioned publications. -->

He wrote a book about the chemistry of terpenes, "Terpene und Campher" (1909).{{fact|date=December 2023}}

Otto Wallach is known for [[Wallach's rule]], [[Wallach degradation]], the [[Leuckart-Wallach reaction]] (which he developed along with [[Rudolf Leuckart (chemist)|Rudolf Leuckart]]) and the [[Wallach rearrangement]].{{fact|date=December 2023}}

== Works ==
* ''Tabellen zur chemischen Analyse''. Weber, Bonn 1880. [http://nbn-resolving.de/urn:nbn:de:hbz:061:2-30977 Digital edition] of the [[University and State Library Düsseldorf]].
** [http://nbn-resolving.de/urn:nbn:de:hbz:061:2-35589 1. Verhalten der Elemente und ihrer Verbindungen. 1880]
** [http://nbn-resolving.de/urn:nbn:de:hbz:061:2-35576 2. Methoden zur Auffindung und Trennung der Elemente. 2. Aufl. von "Hülfstabellen für den chemisch-analytischen Unterricht" 1880]
* ''Terpene und Campher : Zusammenfassung eigener Untersuchungen auf dem Gebiet der alicyclischen Kohlenstoffverbindungen''. 2. Aufl. Leipzig : von Veit, 1914. [http://nbn-resolving.de/urn:nbn:de:hbz:061:2-169647 Digital edition] of the [[University and State Library Düsseldorf]].

== See also ==

* [[List of Jewish Nobel laureates]]

==References==
{{Reflist}}

==External links==
{{Commons category}}
* {{Nobelprize}} including the Nobel Lecture, 12 December 1910 ''Alicyclic Compounds''

<br />{{Nobel Prize in Chemistry Laureates 1901-1925}}
{{1910 Nobel Prize winners}}

{{Authority control}}

{{DEFAULTSORT:Wallach, Otto}}
[[Category:1847 births]]
[[Category:1931 deaths]]
[[Category:Scientists from Königsberg]]
[[Category:Scientists from the Province of Prussia]]
[[Category:19th-century German chemists]]
[[Category:20th-century German chemists]]
[[Category:University of Göttingen alumni]]
[[Category:Humboldt University of Berlin alumni]]
[[Category:Academic staff of the University of Göttingen]]
[[Category:Academic staff of the University of Bonn]]
[[Category:Nobel laureates in Chemistry]]
[[Category:German Nobel laureates]]
[[Category:Jewish Nobel laureates]]
[[Category:Recipients of the Cothenius Medal]]