CLEMENS SCHOPF RALPH E. OESPER University of Cincinnati, Cincinnati, Ohio
ONEof the casualties of the German collapse after World War I1 was the Deutsche Chemische Gesellschaft, which has still not been revived. Also lost was its Berichte, which in 1945 ceased publication with Volume 77. The gap left by the disappearance of this important periodical was too great to be tolerated for long. Consequently, 1947 saw the birth of Chemische Berichte issued nnder private auspices. Its direct succession to the defunct Berichte is indicated by the fact that its first volume was designated as "Jahrgang 80."' The editor chosen for the new, yet old, journal was Clemens Schopf. Born on August 12, 1899, at Gersfeld in the Rhon Mountains, he attended the Humanistic Gymnasium in Fulda and then (1917) began his chemical training a t the Technische Hochschule in Munich. After a short interruption, due to military service, he finished the course and was awarded the degree Diplomingenieur "with distinction." In 1921 he followed his teacher H. Wielaud2 to the University of Freiburg, where he served as assistant and worked on his doctoral dissertation. The latter, which dealt with Lobelia alkaloids, was accepted by the Technische Hochschule in Munich and the Dr. Ing. was conferred in 1923. Dr. Schopf then served as assistant, first at Freiburg and from 1925 at the University of Munich where he habilitated as Privatdozent in 1927. Shortly before his 30th birthday he was called to the Technische Hochschule a t Darmstadt as Professor of Organic Chemistry and Director of the Institut fiir organische Chemie. He has been a t Darmstadt ever since, although flattering offers have come from industry, and other schools (Frankfurt am Main, Karlsruhe, Rostock, Wiirzhurg, Cologne, Gottingen-as successor to Windaus-Berlin) have inquired whether he would be open to negotiations. In 1950 a definite call came from the University of Munich, but although it was a high honor to be considered worthy of succeeding Liehig, von Baeyer, Willstatter, and Wieland the chair was declined because no guarantee could be given that the laboratory, which was completely destroyed during the war, will be rebuilt within a reasonable time. At present, new laboratories for organic chemistry are being built under Professor Schopf's supervision at Darmstadt. His research output has been extensive and important. His first independent studies dealt with the morphine alkaloids. Among other results, he proved definitely -
Volumes 78 and 79, which normally would hase been issued during the interim, were never published. OESPER,R. E., J. CHEM.EDUC., 14, 344 (1937).
that the Robinson formula for morphine is preferable to the Kuorr-Wieland structure. He also elucidated the hydrogenation of thebaine and set up plausible theories of the rearrangement reactions it undergoes when subjected to the action of acids. Finally, he developed an elegant method for again closing the ring of phenols of the morphine series. Other studies dealt with the constitution of usnic acid and other lichen substances, and also with the structure of various alkaloids, among them sama* darine, an animal alkaloid obtained from the venom glands of the European and Alpine salamander. Another of Schopf's fertile ideas was to study a new group of coloring matters, namely those responsible for the yellow, red, and white coloration of certain butterflies (Pieridae) and also, for instance, the yellow color of the European wasps. Together with H. Wieland he isolated the white leucopterin, the yellow xanthopterin, and, with .E. Becker, the red erythropterin, whose constitutions were finally determined by Purrmann. These studies were a significant preliminary step in clearing up the structure of folic acid. By his so-called "syntheses under physiological conditions," Schopf gave organic chemistry a new field of study. Numerous investigations showed that starting with cell-potential organic materials such as aldehydes, amino-aldehydes, 0-0x0 acids, hiogenic amines, etc., nnder mildest conditions in aqueous solution, a t room temperature and in a pH range of approximately 4 to 9, it is. possible to accomplish smooth syntheses of natural materials or of compounds such as tropinone, which may be regarded as preliminary stages of naturally occuring alkaloids. Examples of such syntheses are the production of naturally occurring derivatives of quinoline and isoquinoline, of lobelanine, desoxyvasicine, tropinone, teloidinoue, pseudopelletierine, rutaecarpine, tetrahydroanabasine, and isopelletierine. These procedures frequently require the preparation of previously unknown, very reaitive starting materials, whose general chemical reactions are likewise of interest. For instance, transformations of 2,3,4,5-tetrahydropyridihe(A-piperidine) led among other things to the synthesis of anabasine, ammodendrine, and matridine, the oxygenfree parent substance of matrine. I t is of particular interest to note that several of these syntheses under physiological conditions proceed smoothly only in a narrow pH range around the neutral point, and either do not go at all in strong acid or alkaline solutiou or take another direction. There can be little doubt that syntheses of this t y p e t o
APRIL. 1952
quote Sir Robert Robinson-"have with the chemical processes which in the plant. Professor Schopf holds the "Emil Medal" of the Verein Dentscher
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something to do" lead to alkaloids Fischer Memorial Chemiker. Since
1942 he has been a member of the German Academy of Scientists in Halle, and corresponding member of the Heidelberg and Bavarian Academies. As noted before, he has been Editor of Chemische Berichte since its inception.
