Vladimir PrelogForMemRS[1] (23 July 1906 – 7 January 1998) was a Croatian-Swissorganic chemist who received the 1975 Nobel Prize inchemistry for his research into thestereochemistry of organic molecules and reactions. Prelog was born, and spent his infancy, inSarajevo, and youth inZagreb,Osijek andPrague.[3] He later lived and worked in Prague, Zagreb andZürich.[2]: 2 [4][5]
Early life
The house inSarajevo which Prelog was bornPlaques dedicated toBosnian Nobel laureatesIvo Andrić and Vladimir Prelog atANUBiH
Prelog started elementary school in Sarajevo. In 1915, at the beginning of the first World War, at 9 Prelog moved toZagreb (then part ofAustria-Hungary) with his parents.[3] In Zagreb he graduated from elementary school and, from 1916 to 1919, attended gymnasium there. From 1919 to 1921 his father got a job inOsijek, so family moved there, and Prelog spent those two years attending Osijek gymnasium. There his professor Ivan Kuria sparked his interest and enthusiasm for chemistry.[2]: 2
It was in 1921 that, at the age of 15, and with his teacher’s help, he published a short communication entitled »Eine Titriervorrichtung« (Preparation forTitration) in the prestigious German journal »Chemiker-Zeitung«.[2]: 4
Prelog and Kuria became friends, and continued communicating by letters after Prelog left Osijek.[2]: 2,3 . In a letter from March 16, 1922, Prelog wrote:
I am very busy at the moment. In addition to my routine studies, I have enrolled as an extramural student in the crafts school and I spend whole afternoons three times a week learning how to file, hammer and do all the other things that an eager young locksmith should know. I am doing it to be able to, should I feel like it, return to the homeland after finishing my studies. In this way, I also fence myself off such idle pastimes like dancing.« He continues by describing how he spent the winter enjoying winter sports and how he now, in spring, looks forward to bathing, climbing the Triglav and Grintavec mountains and sailing on lakes Bled and Bohinj. He concludes the letter by giving an enthusiastic account of his visit to the Chemical Analytical Institute in Zagreb: »I think this is the best equipped institute in SHS*. This wealth in platinum (a 300 g water beaker), optical instruments refractometers, spectroscopes, microscopes, etc., etc.) and all the analytical devices that God and the German have created – I have nowhere seen nything like that. It is run by Mr. Eisenhut.[2]
Prelog completed his high school education in Zagreb in 1924. Following his father's wishes, he moved toPrague, where he received his diploma in chemical engineering from theCzech Technical University in 1928. He received hisSc.D in 1929. His teacher wasEmil Votoček, while his assistant and mentor Rudolf Lukeš introduced him to the world oforganic chemistry.[4]: 578
Upon leaving the Czech Technical University, Prelog worked in the plant laboratory of the private firm of G.J. Dríza in Prague; few academic positions were available due to theGreat Depression. Prelog was in charge of the production of rare chemicals that were not commercially available at that time. He worked for Driza from 1929 until 1935. During the time, he got his first doctoral candidate, a company owner at Driza. He performed research in his spare time, investigatingalkaloids incacao bark.[citation needed]
Career and research
The structure of adamantane, first synthesised by Prelog in 1941.
Prelog wanted to work in an academic environment, so he accepted the position of lecturer at the University of Zagreb in 1935.[7] At theTechnical Faculty in Zagreb, he lectured on organic chemistry andchemical engineering.[4]: 578
With the help of collaborators and students, Prelog started researchingquinine and its related compounds. He was financially supported by thepharmaceutical factory "Kaštel", currentlyPliva. He developed a financially successful method of producing Streptazol, one of the first commercialsulfonamides. In 1941, while at Zagreb, Prelog developed the firstsynthesis ofadamantane, ahydrocarbon with an unusual structure that was isolated fromMoravianoil fields.[8][9]
With thischiral resolution, he was able to prove that not onlycarbon but alsonitrogen atoms can be the chiral centre in a molecule, which had been speculated for several years.[10] His relationship with Ružička helped him climb up the academic hierarchical ladder. Starting as an assistant, he becamePrivat-Dozent,Titularprofessor, associate professor, and in 1952 full professor. In 1957 he succeeded Ružička as head of the Laboratory.[11] Since Prelog disliked administrative duties, he implemented rotating chairmanship in the ETH.[4]: 578 Prelog joined the ETH at the right time, since Ružička's Jewish co-workers left the country and went to the United States, so Prelog filled the vacuum they left.[4]: 580
Later work in Switzerland
Prelog's main interest was focused onalkaloids. He found an ideal topic in the elucidation of the structure ofsolanine; he continued his work onCinchona alkaloids and started to investigatestrychnine. He showed thatRobert Robinson's formula for strychnine was not correct. Although the formula he proposed was also not the right one, the discovery increased his international prestige. Later he worked on elucidating the structures of aromaticErythrina alkaloids withDerek Barton, Oskar Jeger andRobert Burns Woodward.[4]: 580
At mid-century, the instrumental revolution necessitated a new approach to structural elucidation. Purely chemical methods had become outdated and had lost some of their intellectual appeal. Recognizing the growing importance of microbial metabolites, Prelog started working on these compounds, which possess unusual structures and interesting biological properties. It led him into antibiotics, and he subsequently elucidated the structures of such compounds asnonactin,boromycin, andrifamycins. For Prelog, natural products represented more than a chemical challenge. He considered them a record of billions of years of evolution.[4]: 580
In 1944 at the ETH, Prelog managed to separate enantiomers with "asymmetric" trivalentnitrogen by columnchromatography at a time when this method was still in its infancy. His work on medium-sized alicyclic and heterocyclic rings established him as a pioneer in stereochemistry and conformational theory and brought an invitation to give the first Centenary Lecture of the Chemical Society in London in 1949. He synthesised medium-sized ring compounds with 8 to 12 members from dicarboxylic acid esters byacyloin condensation and explained their unusual chemical reactivity by a "nonclassical" strain because of energetically unfavorable conformations. He also contributed to the understanding of Bredt's rule by showing that a double bond may occur at the bridgehead if the ring is large enough.[4]: 580–581
In his research of asymmetric syntheses, Prelog studied enantioselective reactions and established rules for the relationship between configuration of educts and products. From Prelog's researches into the stereospecificity of microbiological reductions of alicyclic ketones and the enzymic oxidation of alcohols, he contributed not only to the knowledge of the mechanism of stereospecificity of enzymic reactions in general but also to the structure of the active site of the enzyme.[4]: 581
Specifying the growing number ofstereoisomers of organic compounds became for Prelog one of his important aims. In 1954 he joinedRobert Sidney Cahn andChristopher Kelk Ingold in their efforts to build a system for specifying a particular stereoisomers by simple and unambiguous descriptors that could be easily assigned and deciphered: TheCIP system (Cahn–Ingold–Prelog) was developed for defining absolute configuration using "sequence rules". Together they published two papers. After Cahn and Ingold died, Prelog published a third paper on the topic.[4]: 581 In 1959, Prelog obtained Swiss citizenship.[11]
In 1933, Prelog married Kamila Vitek.[4]: 578 The couple had a son Jan (born 1949).[11]
An intellectual with a wide cultural background, Prelog was one of the 109 Nobel Prize winners who signed thepeace appeal for Croatia in 1991.[citation needed]
Vladimir Prelog died inZürich, at the age of 91. An urn containing Prelog's ashes was ceremoniously interred at theMirogoj cemetery inZagreb on 27 September 2001. In 2008, a memorial to Prelog was unveiled inPrague.[20]
