RESEARCH
Short Cut to Beta-Halosulfones Free-radical addition reactions a r e new one-step routes to beta-halosulfones ïn better than 9 0 % yields
ACS Atvard Paul-Lewis Laboratories
Chemistry
M I N O R J. C O O N
ACS NATIONAL MEETING
A versatile one-step process now takes much of the time and drudgery out of beta-halosulfones synthesis. New free-radical addition reactions— benzenesulfonyl halides with reactive monomers—turn out 90\r-plus yields of beta-chloros bromo-, and iodosulfones. The trick, says Alcoa's J. H. McNarnara, is photochemical initiation. Ke told the Division of industrial and Engineering Chemistry that by selecting the proper sulfonyl halide, chemists can now get 1:1 adducts with almost any reactive monomer, such as styrene, acrylonitrile, acrylates, and vinyl and allyl halides. Order of sulfonyl halide reactivity—iodide > bromide > > chloride. Beta-halosulfones are convenient intermediates to make unsaturated sulfones. Dehydrohalogenation of betahalosulfones with bases like pyridine gives high yields of unsaturated vinyl sulfones, McNarnara points out. These vinyl sulfones, in turn, are very reactive intermediates for such reactions as the Michael's condensation. Here, various anions, such as RO~, amino functions, amines, and malonate ions, condense with olefins activated by the sulfonyl group. Result: a new series of compounds which have not been available before. Beta-halosulfones have found their way into certain specialty commercial uses, such as flame retardants and lube oil additives. The new route is very simple. Equimolar quantities of freshly prepared olefin and sulfonyl halide in a pressure flask are irradiated for a few minutes with a nonfrosted light bulb. In many cases, the beta-halosulfone condensation product crystallizes within a few minutes in better than 90 r/o yields, which indicates a long chain reaction. In a typical reaction, benzenesulfonyl bromide plus styrene in the presence of light energy react to form l-bromo-l-phenyl-2-benzenesul-
Award in Enzyme
Studies into the unknown reaches of biochemistry are never easy. But one young man. only three years out of school, initiated a growing stream of biochemical research findings, which over the past decade have come to be regarded as classics in the field. T h e man is Minor J. Coon, professor of biological chemistry at the University of Michigan, and winner of this year's Paul-Lewis Laboratories Award in Enzyme Chemistry. Coon, now 38, has given science much needed insight into the role of CoA esters in branched chain amino acid metabolism, biosynthesis of cholesterol precursors, mechanism of action of biotin, formation of ketone bodies in diabetes, histidine biosvnthes*s and enzvmatic oxidation of fatty acids and hydrocarbons. When Coon is mentioned, work in .i O I T ri ι τ ι ? i i i e i m i u 01 i.n ;uit_*iit^ci t.riiaui
r ,χ . . :Λ l a i i y axriti
metabolism and CO._» fixation comes to mind. He is responsible for the dis covery of the necessary CO.» fixation step in the metabolism of the amino acid, leucine. His subsequent study of the C 0 2 reaction with highly purified enzymes is considered a high light of biochemical research. The trail in this work was complex. Early papers by Coon were concerned with biosynthesis of histidine by yeast cultures. Later, work with radioactive
carbon isotopes led Coon to the con clusion that h u m a n tissues can synthe size histidine, thus accounting for the fact that Listidiiitr i:> not an essential component of the human diet. Coon then went to work in the dif ficult area of the enzymatic steps in volved in the degradation of branched fatty acids derived from the amino acids, leucine, isoleucine, and valine. H e showed that these branched fatty acids are metabolized as the corre sponding coenzyme A thioesters, with some new enzymatic steps, representing previously unrecognized reaction pat terns, involved in the later stages. Coon was born on July 2 1 . 1921. in Englewood, Colo., and received his ele mentary and secondary education in Denver public schools. Then came a B.A. from the University of Colorado in 1943. Major subject: chemistry; minors in physics and mathematics. It was here that R. G. Gustazon stimu lated Coon's interest in the subject of biochemistry. Advanced training came at the Uni versity of Illinois, where Coon got his Ph.D. in 1946. Major subject this time was biochemistry, with minors in organic chemistry and physiology; his doctoral thesis was on "Amino Acid Re quirements of Man," under the guid ance of W . C. Rose, University of Illi nois biochemistry department. Thus was set the stage for the research to come on amino acids. The year 1947 found Coon an in structor in biochemistry a t the Univer sity of Pennsylvania school of medicine. The move east was quickly followed by marriage (in 1948) to Mary Louise Newburn. In 1952, Coon, now an assistant pro fessor, took leave of absence to work for a year with Severo Ochoa of the biochemistry department of New York University medical school as a Public Health Service Research Fellow. Goal of this work was isolation of enzymes involved in the synthesis and break down of acetoacetate in animal tissues. After a brief return to the Univer sity of Pennsylvania, Coon journeyed to the University of Michigan.
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ACS Award Fritzsche Award
FRANTISEK SORM
Penetrating research in broad fields penes. T h e y have been able to estab of the chemistry of natural products— lish the absolute configuration of the terpenes, steroids, alkaloids, peptides, most important compounds in the and proteins—has brought Frantisek cadinane series. And they have ex Sorm, director of the Institute of Chem plored the chemistry of t h e azulenes and their natural precursors. In t h e istry of the Czechoslovak Academy' of Science, the 1959 Fritzsche Award. course of this work they discovered a For 2 3 years, ever since receiving his new group of sesquiterpenic lactones, ^ doctorate at t h e Technical University the guaianolides. Sorm w a s born in 1913 in Prague and in 1936, Sorm has devoted himself to studies of the structure and synthesis was educated there. After receiving of essential oils and other naturally oc his doctorate from t h e Technical Uni curring complex mixtures. In that versity he w a s assistant professor there time, lie and his coworkers have pub until 1939, when all universities in lished more than 200 papers in these Czechoslovakia were closed down dur ing the German occupation. H e then areas. Sorm's early interest was in the alka joined an industrial research team work loids and he was the first to synthesize ing in organic a n d pharmaceutical several of them. Turning then to the chemistry, and remained there for the steroids and the terpenes, he was among duration of the war. When the universities opened their the first to combine infrared spectros copy with partition chromatography to doors again, Sorm was named (in 1946) professor of organic chemistry at the Λ l U U ν v. o o ?ntial oils and olant extract*! H e found that many of these were far Technical University; in 1950 h e was more complex mixtures than had pre called to t h e chair of organic chemistry viously been assumed; and by obtain at Charles University, Prague. And ing many of the constituent compounds when the Czechoslovak Academy of in the pure state, he was able to point Science was founded in 1952, h e was out errors in previous work on the struc among t h e first to b e elected to full H e was also named tures of some of the sesquiterpenes. membership. This work also led to the discovery of director of the academy's chemical in (In Czechoslovakia, funda medium sized (9-, 10-, and 11-mem- stitute. mental research is conducted in insti b e r e d ) carbon rings in nature. Sorm and his coworkers have also tutes of t h e academy as well as in the m a d e significant contributions to t h e universities.) H e h a s been a member stereochemistry of several sesquiter of the ACS since 1946. :
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fony 1 e t h a n e . In fact, t h e beixzenesulfonyl iodide-styrene reaction is so exothermic that it must b e moderated with a n inert solvent to prevent ex plosion. This suifonyi ualiue reactivity is in sharp contrast with that of the aeyl halides, which d o n o t take part in radical chain additions to olefins. T h e reason for this, M c N a m a r a thinks, is the difference in t h e strength of t h e bond that ties the halogen to the parent radical in the t w o classes of com pounds. Starting materials a r e easy to come by, says McNamara. Benzencsulfonyl chloride is a commercial item, while the bromide a n d iodide are conven iently p i e p a r e d b y t h e action of free halogens on aqueous benzenesuliinate. Conventional routes to beta-halosulfones, such as the oxidation of sul fides and the reaction of the sodium salt of snlfinates with alkyl halides, are tedious; and yields vary from very high to very low, M c N a m a r a explains. M c Namara. in collaboration with P. S. Skell of Pennsylvania State University, uncovered these n e w free-radical ad dition reactions at Pennsylvania State University.
ACS NATIONAL MEETING PetroleuTtrCtamfstnr
Surprises Come front Matrix Isolation Unexpected results have come from use of t h e matrix isolation technique, developed at t h e University of Cali fornia to permit leisurely spectroscopic study of extremely unstable species, in cluding free radicals. UC's George C. Pimentel spelled some of them out ( Award Address ) before the Division of Petroleum Ο herniary. T h e matrix isolation technique uses a suspension of t h e species to b e studied in a solid matrix, which must b e chem ically inert, rigid with respect to diffu sion, and transparent to the spectral region to b e used. At UC, nitrogen, argon, a n d xenon w e r e used a s matrix materials, since infrared spectra w e r e considered of primary importance. W h e n nitrogen o r a rare gas matrix is used, t h e sample is prepared "by freez ing quickly a gaseous mixture of a small amount of t h e material t o b e
