CV and Obituary

Vladimir Prelog

(* July 23, 1906 in Sarajevo, Austria-Hungary; † January 7, 1998 in Zürich, Switzerland)

Vladimir Prelog was a Swiss chemist of Croatian origin. In 1975 he received - together with John W. Cornforth – the Nobel Prize for chemistry for his work on the stereochemistry of organic molecules and reactions.

His Life

In 1915, Prelogs family moved to Zagreb where he visited the High School. From 1924 to 1929, he studied chemistry at the University for Chemical-Technological Engineering of the Czech Technical University of Prague and attained a doctorate with Emil Votoček. First he worked in Prague as a scientific assistant in a laboratory, where he could work but not do any research. In 1933, he married 1933 Kamila Vítek in Prague. In 1935, he changed as a lecturer to the University of Zagreb. After the invasion of the Germans in Zagreb in 1941, Prelog wanted to leave Zagreb. Leopold Ruzicka, professor of the ETH Zurich and Nobel Laureate for chemistry (1939), invited him to Zurich. There he began to work in the laboratory for organic chemistry of the Swiss Federal Institute of Technology. First he worked as an assistant, later he became Assistant Professor and in 1950 he was appointed „Titularprofessor“, and again later he was appointed Associated Professor. In 1952, he became full Professor ad personam and in 1957, he became Ruzickas successor as the head of the laboratory for organic chemistry. In 1976, he retired.

In January 1949, Prelogs son was born, and in 1959 he became a Swiss citizen. In 1998, Prelog died at the age of 92 in Zurich. On September 27, 2001, his ashes were brought to the Mirogoj cemetery in Zagreb.

His Work

With his scientific efforts, he perpetuated the research of Leopold Ruzicka. He was active in the area of stereochemistry of natural substances, in particular that of alkaloids and antibiotics. The stereochemistry examines the spatial arrangement of the atoms in the molecules. It would like to obtain as exact an image of the shape of molecules as possible and makes thereby a substantial contribution to the awareness of the connection between structure and characteristics of the subject. It is not a special field of organic chemistry, but penetrates as substantial opinion all areas of chemistry. Prelog acquired special merits in the research of the so-called „middle rings “, ring connections with 8 to 14 carbon atoms, with which he could close a gap between „the classical rings“ with 6 C-atoms and the large rings with 16 or 18 C-atoms, for which discovery Ruzicka was honoured with the Nobel Prize.

For Prelog, the basic research was also a socially relevant activity, especially when later on for example medicines were developed to fight tuberculosis or the leprosy. The development of effective antibiotics was based on his work. Among his coworkers and colleagues, Vladimir Prelog was known to be an incalculable humorist who bubbled over with ideas. Besides his devotion for his scientific work, he collected stamps, was an enthusiastic photographer and loved the chamber music. He also found time and interest for sports. Professor Prelog lived as a convinced pedestrian, non-driver and non-smoker. In 1976, Prelog retired, but did by no means withdraw from research.

Professor Prelog received innumerable honors in the course of his scientific activity. Besides the Nobel Prize for chemistry in 1975, he among other things was honoured with an honorary doctor by the Universities of Zagreb, Liverpool and Paris as well as by the Weizmann Institute for Sciences in Rehovot, Israel. In addition, he was „Membre étranger“ of the académie des sciences in Paris, as well as a member of the Royal Society in London, the United States National Academy of Sciences, the Leopoldina Hall and the Academy of Sciences of the USSR. In 1964, Prelog had been distinguished with the Marcel Benoist Prize, the oldest science prize of Switzerland. In 1986, he became honorary member of the Croatian Academy of Sciences and Arts.

(copyright © Wikipedia)

Obituary by Jack D. Dunitz

Nature 391, 542 (5. Februar 1998)

Until quite recently, the nonagenarian Vladimir Prelog was a familiar figure in the chemistry building of the ETH. Conspicuous in his immaculate, white laboratory coat, he could be seen in the corridors or in the Chemiebar, where he drank his coffee most mornings and afternoons. New students used to ask: "Who is that elderly gentleman in the white lab coat? Is he a laboratory technician?" On being told that this was Prelog, the Nobel-Prize winner, they were impressed, for they knew his name from the first-year lectures. We shall see him no more. Vladimir Prelog, one of the great organic chemists of our century, died on January 7, 1998, after a short illness. He is survived by his wife and son.

A child of the old Austro-Hungarian empire, Prelog was born in Sarajevo on 23 July 1906. He was present at the fateful visit of the Austrian crown prince, Archduke Franz Ferdinand, on 28 June 1914, when, waiting to throw flowers in front of the state carriage, he heard the shots that presaged the end of that era. His school years were passed in Zagreb, after which he studied chemistry at the Prague Institute of Technology, obtaining his doctorate in 1929 with Emil Votoek but being influenced more by Rudolf Lukes, who led him into the chemical world of alkaloids. It was the time of the great depression, and Prelog supported himself 'semi-legally' by preparing chemicals in a commercial laboratory whose owner and director became Prelog's first doctoral student. In 1935, he moved back to Zagreb, where he taught at the university, first as lecturer and then as professor. Meanwhile, he was associated with a fledgling chemical company in Zagreb (which later developed into Pliva, the largest Yugoslav pharmaceutical company). His commercial preparation of sulphanilamide (Streptazol) brought the financial support needed for his research.

In 1941, after the German occupation of Yugoslavia, he managed to escape under adventurous circumstances to Zürich in neutral Switzerland. There, at the organic chemistry laboratory of the Federal Institute of Technology (ETH) under his fellow countryman Leopold Ruzicka, he found a temporary refuge, which gradually developed into a home in every sense of the word. If the ETH gave Prelog a home, Prelog brought fame to the ETH, with which he was associated for more than 50 years. After Ruzickas retirement in 1957, Prelog became head of the laboratory but soon decided to share his powers and his responsibilities, with his younger colleagues — this was then in continental Europe a mildly revolutionary step for the director of a chemistry institute. After his retirement in 1976 Prelog promptly registered as a special student (Fachhörer) in order to continue his scientific work. At the ETH, this is not regarded as an automatic perquisite of a retired professor; it is a privilege for which one may be grateful. Prelog's 1991 autobiographical sketch was entitled, "My 132 Semesters of Chemistry Studies". Renowned as teacher and researcher, he regarded himself as a student to the end.

As an organic chemist, Prelog bridged the gap between the classical tradition and the modern school. When he began his long research career, molecular structure was still being inferred by classical methods, that is to say, by subtle but indirect arguments from chemical reactivity. Success in this area required profound knowledge of chemistry, rigorous logic and, sometimes, a flight of inspiration as well. By mid-century, physical methods — molecular spectroscopy, X-ray analysis and, later, nuclear magnetic resonance — were beginning to displace the traditional chemical methods. Prelog's early work on the structure of alkaloids from Cinchona, Strychnos and other sources was done by classical methods, whereas his later studies of metabolic products of microorganisms were largely based on the newer physical methods. It was mainly through his influence that organic chemistry at the ETH was swift to take advantage of the new techniques.

For his contributions to stereochemistry, Prelog shared the 1975 Nobel prize in chemistry with J. W. Cornforth. Stereochemistry is not so much a branch of chemistry as a way of looking at the science, an explicit concern with molecular shape. Prelog was always fascinated by the spatial forms of organic molecules. One of his early feats in Zagreb was the synthesis of adamantane, with its highly symmetrical molecular structure. Later, in Zürich, he was one of the first to see the importance of steric effects on the reactivity of molecules with medium and large ring systems — for example, the non-reactivity of cyclodecanone towards hydrogen cyanide compared with the ready formation of cyanhydrins of smaller and larger rings. This led him to conformational analysis, and indeed, together with D. H. R. Barton, he was one of the founders of this important branch of modern chemistry. A feature of his later work was the emphasis on steric bulk as a factor in controlling the course of asymmetric synthesis and as a basis for understanding stereospecific reactions in general.

In the mid-1950s, these interests led Prelog to develop, together with his British colleagues R. S. Cahn (then editor of The Chemical Society) and C. K. Ingold, the now universally adopted 'CIP' system of rules for specifying the sense of chirality at tetrahedral stereogenic centres. Towards the end of his life, Prelog was preoccupied with the complexities inherent in this system. There can be few organic chemists of his generation who have had the intellectual strength to master the more mathematical, graph-theoretical aspects of the models they use to describe molecular structures and their interconversions.

Not only as a chemist but also as a person, Prelog made a powerful impression on others. He was admired as a scientist and loved as a person by a multitude of friends from all over the world. A formidable lecturer and talker in general, renowned for his inexhaustible supply of jokes, Yugoslavian folk-sayings, and anecdotes about every famous chemist who has ever lived, he captivated all. Ambitious as far as science was concerned, he was uninterested in the exercise of power — he said that he disliked making decisions that affected other people. He was seldom provoked to anger and claimed to have an unusually low adrenaline level. But, of course, behind this outward appearance there was a serious, introspective side. His ironic and often self-deprecatory humour was frequently a protective wall for his inner self. Sadly, his last years were clouded by the tragic course of events in his native land, which caused him immeasurable grief and sadness.