Georg Wittig - Journal of Chemical Education (ACS Publications)

Presents the life and scientific contributions of Georg Wittig. ... Green Aqueous Wittig Reaction: Teaching Green Chemistry in Organic Teaching Labora...
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GEORG WITTIG RALPH E. OESPER University of Cincinnati, Cincinnati, Ohio

SMALL incidents sometimes have important consequences. When Georg Wittig was in the later years of the elementary school, a copy of "Chemische Experimente aus dem Alltag" (chemical experiments from everyday life) came into his hands. The first experiment in this little manual, namely the fact that redcabbage water turns green with soda and that the red color is restored by vinegar, impressed him so much that he could never again tear himself loose from the fascinations of chemistry. The pleasure of making observations and the joy of chemical manipulations became the foundation of his future research activities. This process of developing into a scientist was interrupted by military service and imprisonment (1916-19) but it was never subjugated by other distractions or interests. Georg (Friedrich Karl) Wittig was horn a t Berlin on June 16, 1897. His father was an artist; his mother was very devoted to music. Consequently, his youth was spent in a cultural atmosphere. The German youth movement "Wandervogel" (migratory birds) played a significant part, in his education; it awakened in him an appreciation of nature and taught him the value of true comradeship. The combination of humanistic training, art, and love of nature was responsible in great measure for the shaping of his future career. After he finished the course a t the humanisticGymnasium at Cassel in 1916 his education was interrupted by the war. I n 1920 he eagerly began his professional training a t the University of Marburg. Since three other members of the family were also in school, his financial resources were skimpy. He devoted himself solely to science and found his recreation a t the piano in the evenings. His principal teacher, Karl von Auwers (1863-1939),' under whom he took his doctorate in 1923, was reserved, strict, and just. He taught his students t o work cleanly. While Wittig was serving as assistant in the inorganic division, vou Auwers encouraged him to prepare himself for a Privatdozentship. The habilitation was achieved in 1926; the underlying research was in a purely preparative field and dealt with chromone and cumariu syntheses. Many suggestions came from Wittig's close friend, the brilliant thinker and enthusiastic experimenter, K. Ziegler2 and also from the Gottingen friend, W. H i i ~ k e lwhose ,~ comprehensive information and critical attitude were For biaera~hicaldet& see MEERWEIN. H.. Ber.. 72A. 111-21 (1939);TA&, J., Chem. ~nd., 17,838dh (i939). a See J. CHEM.EDUC.,25, 510 (1948). aZbzd.,27, 625 (1950).

oflered to Wittig during their excursions on foot. H. Meerwein, who succeeded vou Auwers a t Marburg, made Wittig enthusiastic about his ideas, which came into their own somewhat later and which also had an effect on Wittig's investigations. These contacts with the theoretical side of chemistry resulted in Wittig's excellent "Stereochemie" (388 pages), which was published in 1930. I n 1932 Wittig went to Braunschweig, where he was Division Head a t the Technische Hochschule, and only then did he secure enough co-workers to realize his ideas. He soon became a close friend of the head of the Institut, K. Fries, a particularly gifted experimenter. At this time, the political unrest was reaching even into the institutions of higher learning and many of the faculty members were greatly concerned by the possible implications of the new state doctrines. When Wittig was called t o the University of Freiburg in 1937 as associate professor of organic chemistry, he found that the political impacts were much less noticeable there than in some of the other schools. Here his scientific horizon was greatly widened by the close contact with macromolecular chemistry, a field which the head of the Institut, H. Staudinger4 had founded and was developing to a considerable extent. I n 1944 Wittig was called to his present position, head of the department and ordinary professor a t the University of Tiibingen. From the very beginning of his research career Wittig has made it a cardinal principle to experiment and to experiment again and again, with no regard to present conditions, technical applicability, or possible outside recognition. Results awakened ideas which a t times led him astray, but sometimes they resulted in further advances. This interplay between experiment and imagination led him to an involuntary but logical sequence in his research activities. He began with the cleavage of the chromones to dicarbonyl compounds by means of alcoholate. I n one case he succeeded in preparing the four possible stereochemical dioximes. The proof of their configurations brought him into contact with the interesting discovery by J. Meisenheimer (18761935), who camed out an independent proof of the configuration by means of the ozonide splitting of triphenyl isoxaaole. Since a t that time Wittig thought it possible that the ringopening of the energy-rich ozonide would lead to the flipping of the hydroxyl group t o the opposite side, 4 Staudinger was awarded the Nobel Prize for this contribution; see the numerous appreciations published in 1953; also J. CHEM.EDUC.,16. l(1939).

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he studied the ozonization of isoxazoles in additional a series of extended researches dealing with the metalinstances but found no confirmation of his ideas. They lation of phenol ethers; they led t o the phenomenon of led him, however, to the new idea of investigating the the halogen-lithium exchange reactions and to reartension in those rings which exhibit a loosening due t o rangements within the molecule. I n this way there radical-forming substituents on a C-C bond. This came into being an organic aniono chemistry, whose connection between ring tension and radical formation de~ielopmentis a t present the chief aim of Wittig's led to a series of studies, which spread in a variety of researches. He is also working on the problems of directions. During the synthesis of w,w' tetraphenyl- autoxidation and its inhibition and on various topics enepolyenes with their somewhat striking characteris- in radical- and stereochemistry. The working out of the research plans of a university tics, there arose the problem of valence tautomerism, whose limiting validity had been outlined by Wittig as professor usually requires the collaboration of a staff of early as 1930. The new investigation led him to the co-workers recruited from doctoral candidates and redevelopment of new methods of obtaining polyene search fellows. The relative lateness of Wittig's chains, a problem that is still claiming part of his at- maturing process and the external conditions of the country had the result of making him 35 before he tention. This work also took him into the chemistry of the could unfold in the scientific sense. As a rule, about lithium-organo compounds. In conformity with the a dozen young men are working with him, a number which in his opinion is optimal for the greatest effischeme ciency of the teacher and the maximum benefit to the Rod-COnR HO(CsB)lCC(CsHs)nOH student. He found that the veterans who returned the pertinent glycols need to be prepared if poly- to the universities after the political collapse of Gerenes are to be obtained from dicarboxylic esters. many were outstanding, since the resolve to study Although the reaction of the diesters with phenyl under the most difficult conditions is equivalent to a magnesium bromide gave but small yields of the gly- careful screening. He feels that special thanks are due cols, the reaction proceeded much better when phenyl- to such men when their scientific collaboration led to lithium was employed, a reagent that had recently been results which gained respectful recognition in the chemimade readily available through the work of K. Ziegler. cal world. Professor Wittig refused a call to head the Institut When this reagent was replaced by panisyl-lithium, however, prepared from lithium and p-anisyl bromide, at the University of Freiburg in 1950 because the buildunravelable mixtures again resulted. A surprising ing still needed to be reconstructed. In 1953 he was product was obtained when benzophenone was allowed elected corresponding member of the Bavarian Acadto react with the organometallic solution, namely, emy of Sciences, and in this same year the Gesellschaft bromo-anisyl-diphenyl carbinol instead of the expected Deutscher Cherniker awarded him its Adolf von Baeyer panisyl-diphenyl carbinol. This discovery ushered in memorial medal.

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