Carl Djerassi Papers SC0348
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A Facile Procedure for the Generation of Dichlorocarbene from the Reaction of Carbon Tetrachloride and Magnesium Using Ultrasonic Irradiation
Molecules 2003, 8, 608-613 molecules ISSN 1420-3049 http://www.mdpi.org A Facile Procedure for the Generation of Dichlorocarbene from the Reaction of Carbon Tetrachloride and Magnesium using Ultrasonic Irradiation Haixia Lin *, Mingfa Yang, Peigang Huang and Weiguo Cao Department of Chemistry, Shanghai University, Shanghai, 200436, P.R. China *Author to whom correspondence should be addressed: e-mail [email protected] Received: 7 April 2003; in revised form: 7 July 2003 / Accepted: 20 July 2003 / Published: 31 July 2003 Abstract: An improved method for the generation of dichlorocarbene was developed that utilizes ultrasound in the reaction of carbon tetrachloride with magnesium. High yields of gem-dichlorocyclopropane derivatives can be obtained in the presence of olefins by this method. Keywords: Dichlorocarbene; gem-dichlorocyclopropanes; ultrasonic irradiation; olefin addition; magnesium Introduction Gem-dichlorocyclopropanes are valuable intermediates in organic synthesis [1,2]. They are typically prepared by the addition of dichlorocarbene to olefins under phase-transfer catalysis conditions [3-5]. Sonochemical generation of dichlorocarbene has also been reported [6-8]. The reactions of dichlorocarbene with olefins in solid-liquid two-phase systems using ultrasonication usually afford high yields of double-bond addition products. In addition, excellent yields of diadducts have been obtained from dienes and dichlorocarbene under ultrasonication and phase-transfer catalyst [9]. Molecules 2003, 8 609 Previously, we reported a novel route for the generation of dichlorocarbene by the reaction of carbon tetrachloride with magnesium in a neutral medium and hypothesized that the mechanism of these reactions might involve a single electron transfer [10]. However, these reactions suffered from several experimental drawbacks: some of the major ones being the sudden exotherm that occurs after an unpredictable induction period, foaming, and in some cases, the use of iodine as the activating agent. -
Chloroform 18.08.2020.Pdf
Chloroform Chloroform, or trichloromethane, is an organic compound with formula CHCl3. It is a colorless, sweet-smelling, dense liquid that is produced on a large scale as a precursor to PTFE. It is also a precursor to various refrigerants. It is one of the four chloromethanes and a trihalomethane. It is a powerful anesthetic, euphoriant, anxiolytic and sedative when inhaled or ingested. Formula: CHCl₃ IUPAC ID: Trichloromethane Molar mass: 119.38 g/mol Boiling point: 61.2 °C Density: 1.49 g/cm³ Melting point: -63.5 °C The molecule adopts a tetrahedral molecular geometry with C3v symmetry. Chloroform volatilizes readily from soil and surface water and undergoes degradation in air to produce phosgene, dichloromethane, formyl chloride, carbon monoxide, carbon dioxide, and hydrogen chloride. Its half-life in air ranges from 55 to 620 days. Biodegradation in water and soil is slow. Chloroform does not significantly bioaccumulate in aquatic organisms. Production:- In industry production, chloroform is produced by heating a mixture of chlorine and either chloromethane (CH3Cl) or methane (CH4). At 400–500 °C, a free radical halogenation occurs, converting these precursors to progressively more chlorinated compounds: CH4 + Cl2 → CH3Cl + HCl CH3Cl + Cl2 → CH2Cl2 + HCl CH2Cl2 + Cl2 → CHCl3 + HCl Chloroform undergoes further chlorination to yield carbon tetrachloride (CCl4): CHCl3 + Cl2 → CCl4 + HCl The output of this process is a mixture of the four chloromethanes (chloromethane, dichloromethane, chloroform, and carbon tetrachloride), which can then be separated by distillation. Chloroform may also be produced on a small scale via the haloform reaction between acetone and sodium hypochlorite: 3 NaClO + (CH3)2CO → CHCl3 + 2 NaOH + CH3COONa Deuterochloroform[ Deuterated chloroform is an isotopologue of chloroform with a single deuterium atom. -
Carl Djerassi: Chemist and Entrepreneur
Carl Djerassi: Chemist and entrepreneur Eugene Garfield 534 CHEMTECH SEPTEMBER 1983 Much has been said about the scientific entrepreneur. established a precedent for the widely used fragment coding Although the term ordinarily is applied to the person who system employed in the Index Chemicus Registry System has been successful in business—one thinks of Thomas (ICRS) and other systems. Edison or Edwin Land, among others—there also are At the end of the 1940s, much of the excitement centered scientific entrepreneurs in the academic community. It is on the discovery that cortisone could alleviate arthritis not often that one finds a scientist who can fit both symptoms. The chemical was derived from animal bile, but descriptions. To maintain a credible academic existence one initially in amounts too small for treating this chronic, needs enormous dedication and energy; to function in a widespread disease. Scientists around the world were racing scientifically oriented business these qualities as well as to find a more practical method of synthesis. In 1951, significant managerial competence are needed. That rare Djerassi and his team at Syntex won the race; they found a combination of qualities is found in my friend Carl relatively simple way to make cortisone using a readily Djerassi. available raw material, the Mexican yam (2). I recently had the honor of speaking informally at an That same year, Djerassi's team synthesized another unusual event. The numerous friends and collaborators of compound, which received much less attention at the time. Djerassi attended a party celebrating the publication of his They named it "norethisterone," and it was to become the thousandth paper. -
The 1990 Nobel Prize Winners
Current CX3mrnerits” EUGENE GARFIELD INSTITUTE FCR SCIENTIFIC INFORMATGW 3YJ1 MARKET ST PHILAOELFHIA, PA 19104 The 199Q Nobel Prize Winners: A Citationist Retrospective Number 11 March 18, 1991 For more than a decade, we have devoted Before the awards were announced last essays to each year’s Nobel Prizes. These year, the biweekly newspaper ?% Scien- reports, usually published six months or tkt @ published a series of axticles in which more after the prize, have provided a unique Nobel Prize contenders were listed, based citationist perspective on the wimers. In ad- on citation frequency and predictor dition to identifying their most-cited works, awards.$7 One would think that with all of especially Citation Clussics ~, we have the non-Nobel awards that abound,g.g there highlighted work that has influenced key re- would be few recipients not in that category. search fronts.1 Nevertheless, this does occur km time to When pertinent, we’ve also listed the time. winners’ contributions to the review litera- One interesting aspect of this year’s ture. And+whe~ possible, we’ve contacted awards is the relatively low level of citations the Nobelists or close colleagues to de- for several of the winners. This could be due termine whether or not our data rein- to factors similar to those of the famous forced or contradicted perceptions of de- Watson and Crick paper in 1953,10 for layed recognition, as in the case with which they teceived the 1%2 Nobel Prize in Barbara Mc(lintock.z Her 1983 Nobel for physiology or medicine. It had been cited physiology or medicine may have been de- just under 1,100 times when we last studied layed, but she was widely recognized in the it.11This is an indication of obliteration by genetics community. -
Robert Burns Woodward
The Life and Achievements of Robert Burns Woodward Long Literature Seminar July 13, 2009 Erika A. Crane “The structure known, but not yet accessible by synthesis, is to the chemist what the unclimbed mountain, the uncharted sea, the untilled field, the unreached planet, are to other men. The achievement of the objective in itself cannot but thrill all chemists, who even before they know the details of the journey can apprehend from their own experience the joys and elations, the disappointments and false hopes, the obstacles overcome, the frustrations subdued, which they experienced who traversed a road to the goal. The unique challenge which chemical synthesis provides for the creative imagination and the skilled hand ensures that it will endure as long as men write books, paint pictures, and fashion things which are beautiful, or practical, or both.” “Art and Science in the Synthesis of Organic Compounds: Retrospect and Prospect,” in Pointers and Pathways in Research (Bombay:CIBA of India, 1963). Robert Burns Woodward • Graduated from MIT with his Ph.D. in chemistry at the age of 20 Woodward taught by example and captivated • A tenured professor at Harvard by the age of 29 the young... “Woodward largely taught principles and values. He showed us by • Published 196 papers before his death at age example and precept that if anything is worth 62 doing, it should be done intelligently, intensely • Received 24 honorary degrees and passionately.” • Received 26 medals & awards including the -Daniel Kemp National Medal of Science in 1964, the Nobel Prize in 1965, and he was one of the first recipients of the Arthur C. -
Gas-Solid Alkali Destruction of Volatile Chlorocarbons
LA-13042-MS Gas-Solid Alkali Destruction of Volatile Chlorocarbons c£lVi •% to BO Los Alamos NATIONAL LABORATORY Los Alamos National Laboratory is operated by the University of California for the United States Department of Energy under contract W-7405-ENG-36- An Affirmative Action/Equal Opportunity Employer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither The Regents of the University of California, the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by The Regents of the University of California, the United States Government, or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of The Regents of the University of California, the United States Government, or any agency thereof. The Los Alamos National Laboratory strongly supports academic freedom and a researcher's right to publish; therefore, the Laboratory as an institution does not endorse the viewpoint of a publication or guarantee its technical correctness. DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best aTaiiable original document. LA-13042-MS UC-901 Issued: December 1995 Gas-Solid Alkali Destruction of Volatile Chlorocarbons Jerry Foropoulos, Jr. -
Phi Beta Kappa Visiting Scholars 1956-57- 2016-2017 (61 Years)
Phi Beta Kappa Visiting Scholars 1956-57- 2016-2017 (61 years) 2016-2017 (112 visits) Adorno, Rolena Spanish/Latin American literatur Yale Bialek, William physics Princeton Ehrman, Bart D. religion, New Testament UNC-Chapel Hill Grosz, Barbara J. computer science Harvard Hochschild, Jennifer L. political science Harvard Kitcher, Philip philosophy Columbia Lester, Marsha I. chemistry Penn Morse, Nora Naranjo fine arts, poetry, sculpture Espanola, NM Rodgers, Daniel T. American history & culture Princeton Sabloff, Jeremy A. anthropology, Maya Penn Weiman, David F. economic history Barnard Wexler, Laura American studies Yale Witt, John Fabian law, American history Yale Wright, Patricia anthropology/primatology SUNY, Stony Brook Xiao, Shuhai geobiology/paleobiology Virginia Tech 2015-2016 (100 visits) Michael Bérubé English, disability studies Penn State Caroline Bruzelius art, art history Duke David K. Campbell physics, engineering Boston U. Hazel V. Carby African American studies Yale Carol Greenhouse anthropology, sociocultural Princeton David B. Grusky sociology, inequality, poverty Stanford Rigoberto Hernandez biochemistry, diversity studies Georgia Tech Mae Ngai history, Asian American studies Columbia Judith Resnik law Yale Timothy Rowe paleontology, geology UTAustin Larry A. Silver art history, Renaissance Penn Harold W. Stanley political science, elections Southern Methodist Richard Sylla American economic history NYU Blaire Van Valkenburgh vertebrate paleonbiology UCLA Vincent L. Wimbush religion Inst.SignifyingScriptures 2014-2015 (96 visits) Jeffrey C. Alexander sociology Yale William Y. Arms computer science Cornell Wendy Brown political science UCBerkeley Caroline Bruzelius art, art history Duke Philip J. Deloria history, American Indian Michigan Gerald Graff English, education Illinois at Chicago Kathleen McGarry economics, aging UCLA Gregory A. Petsko neurology, neuroscience Cornell Med. -
Carl Djerassi, Pictured Here with Artwork from His Collection
Carl Djerassi, pictured here with artwork from his collection. This sculpture, by artist Niki de Saint Phalle, is entitled “Wise Man.” Photograph by Walter van Schalkwijk. Carl Djerassi: Renaissance Scientist Par Excellence by Krishnan Rajeshwar and Walter van Schalkwijk arl Djerassi was born in Vienna, Austria, and received his Fritzsche Award (1960), Award for Creative Invention (1973), education at Kenyon College (AB summa cum laude, Award in the Chemistry of Contemporary Technological Prob- 1942) and the University of Wisconsin (PhD, 1945). After lems (1983), Priestley Medal (1992), Willard Gibbs Medal (1997), four years as research chemist with CIBA Pharmaceutical and Othmer Gold Medal (2000). Co. in Summit, New Jersey, he joined Syntex, S.A., in Carl Djerassi is a member of the U.S. National Academy of Mexico City in 1949 as associate director of chemical Sciences and of its Institute of Medicine, as well as a member of Cresearch. In 1952, he accepted a professorship at Wayne State the American Academy of Arts and Sciences, the Royal Swedish University, and in 1959 his current position as professor of Academy of Sciences, and many other learned societies. He has chemistry at Stanford University. received 18 honorary doctorate degrees from various academic Concurrently with his academic positions, he also held var- institutions around the world. ious posts at Syntex during the period 1957-1972, including that Djerassi has embarked on a second career in writing of president of Syntex Research (1968-1972). In 1968, he helped including five “science-in-fiction” novels: Cantor’s Dilemma; The found Zoecon Corporation, a company dedicated to developing Bourbaki Gambit; Marx, Deceased; Menachem’s Seed; and NO. -
Lecture 13 Electrophilic Aromatic Substitution I 5.1 Principles
NPTEL – Chemistry – Principles of Organic Synthesis Lecture 13 Electrophilic Aromatic Substitution I 5.1 Principles The reaction occurs in two stages: the electrophile adds to one carbon atom of the aromatic ring, yielding a carbocation in which the positive charge is delocalized, and a proton is then eliminated from the adduct. H E H E H E E -H E 5.2 Formation of Carbon-Carbon Bonds 5.2.1 Friedel-Crafts Acylation Acylation of aromatic rings is generally peroformed using acid chloride or acid anhydride as an acylating agent in the presence of Lewis acid. O Z RCOCl, AlCl Z 3 R H2O Mechanism AlCl3 RCOCl RC=O + AlCl4 H H RC=O COR Z Z COR Z Joint initiative of IITs and IISc – Funded by MHRD Page 1 of 26 NPTEL – Chemistry – Principles of Organic Synthesis In some circumstances, carboxylic acid is used as an acylating agent in the presence of a proton acid. HO OH O 2 PhOH, H2SO4 O O -H2O O O Phenolphthalein Indicator Intramolecular reactions are of particular value to construct cyclic systems. These reactions are usually carried out using dibasic acid anhydrides. For example, the synthesis -tetralone has been accomplished from benzene and succinic anhydride using AlCl3 in 80% yield. O O OH OH AlCl3 reduction + O O O O SOCl2 Cl AlCl3 O O Joint initiative of IITs and IISc – Funded by MHRD Page 2 of 26 NPTEL – Chemistry – Principles of Organic Synthesis Examples: 5 mol% Tb(OTf)3 CO H 2 PhCl O D.-M. Cui, C. Zhang, M. Kawamura, S. -
The Dichlorocyclopropanation of 3-Methyl-1-Cyclohexene and 4-Vinyl-1- Cyclohexene Using Water Soluble Multi-Site Phase Transfer Catalyst-A Kinetic Study
Int.J.Curr.Microbiol.App.Sci (2014) 3(9) 211-223 ISSN: 2319-7706 Volume 3 Number 9 (2014) pp. 211-223 http://www.ijcmas.com Original Research Article The dichlorocyclopropanation of 3-methyl-1-cyclohexene and 4-vinyl-1- cyclohexene using water soluble multi-site phase transfer catalyst-A kinetic study K.Shanmugam* and E.Kannadasan Deptartment of Chemistry, Government Arts College, Chidambaram, TamilNadu, India *Corresponding author A B S T R A C T The present study focuses the attention towards the utility of multi-site phase K e y w o r d s transfer catalyst (MPTC), is demonstrated by studying hydroxide-ion initiated reaction like dichlorocarbene addition to olefins. The formation of the product was Multi-site phase monitored by GLC.Dichlorocyclopropanation of 3-methyl-1-cyclohexene and 4- transfer catalysts, vinyl-1-cyclohexene catalysed by multi-site phase transfer catalyst carried out in Dichlorocyclopro biphasic medium under pseudo-first-order conditions by keeping aqueous sodium panation, hydroxide and chloroform in excess. The effect of various experimental parameters 3-methyl-1- on the rate of the reaction has been studied. Also thermodynamic parameters such cyclohexene;4- as S#, G# and H# were evaluated; based on the experimental results, a suitable vinyl-1- mechanism is proposed.It also deals in greater detail on the kinetic aspects of cyclohexene, Kinetics chosen reactions. An attempt has been made to compare the ability of MPTC-1 with MPTC-II and single-site PTC for dichlorocarbeneaddition to olefins like 3- methyl-l-cyclohexene and 4-vinyl-l-cyclohexene. Introduction The reaction of chloroform with strong to be generated in, or transferred to the bases to generate synthetically useful organic phase, where its reaction with 3- dichlorocarbene normally requires methyl-l-cyclohexene is much greater than anhydrous conditions to avoid its rapid with water addition of dichlorocarbene to 3- hydrolysis (Reeves et al., 1976). -
Carbene Rearrangements: Intramolecular Interaction of a Triple Bond with a Carbene Center
An Abstract OF THE THESIS OF Jose C. Danino for the degree of Doctor of Philosophy in Chemistry presented on _Dcc, Title: Carbene RearrangementE) Intramolecular Interaction of a Triple Bond with aCarbene Center Redacted for Privacy Abstract approved: Dr. Vetere. Freeman The tosylhydrazones of2-heptanone, 4,4-dimethy1-2- heptanone, 6-heptyn-2-one and 4,4-dimethy1-6-heptyn-2- one were synthesizedand decomposed under a varietyof reaction conditions:' drylithium and sodium salt pyrolyses, sodium methoxide thermolysesin diglyme and photolyses of the lithium salt intetrahydrofuran. The saturated ana- logues 2-heptanone tosylhydrazoneand its 4,4-dimethyl isomer afforded the alkenesarising from 6-hydrogeninser- product distribution in the tion. It was determined that differ- dry salt pyrolyses of2-heptanone tosylhydrazone was ent for the lithiumand the sodium salts. However, the product distribution of thedry sodium salt was verysimilar diglyme to product distributionobtained on thermolysis in explained by a with sodium methoxide. This difference was reaction of lithium bromide(present as an impurity inall compound to the lithium salts)with the intermediate diazo afford an organolithiumintermediate that behaves in a some- what different fashionthan the free carbene.The unsaturated analogues were found to produce a cyclic product in addition to the expected acyclic alkenes arising from 3-hydrogen insertion. By comparison of the acyclic alkene distri- bution obtained in the saturated analogues with those in the unsaturated analogues, it was concluded that at leastsome cyclization was occurring via addition of the diazo moiety to the triple bond. It was determined that the organo- lithium intermediateresulting from lithium bromide cat- alyzed decomposition of the diazo compound was incapable of cyclization. -
Kenyon Collegian College Archives
Digital Kenyon: Research, Scholarship, and Creative Exchange The Kenyon Collegian College Archives 2-5-2015 Kenyon Collegian - February 5, 2015 Follow this and additional works at: https://digital.kenyon.edu/collegian Recommended Citation "Kenyon Collegian - February 5, 2015" (2015). The Kenyon Collegian. 2369. https://digital.kenyon.edu/collegian/2369 This News Article is brought to you for free and open access by the College Archives at Digital Kenyon: Research, Scholarship, and Creative Exchange. It has been accepted for inclusion in The Kenyon Collegian by an authorized administrator of Digital Kenyon: Research, Scholarship, and Creative Exchange. For more information, please contact [email protected]. KCDC impresses with mainstage spectacle, Bakkhai Pg. 5 Serving Kenyon College and Gambier, Ohio Since 1856 2.5.15 VOLUME CXLII NO. 16 The Collegian 16 pages Today and tomorrow, the Destigmatizing mental health issues Board of Trustees meets to discuss Kenyon’s present and future. Some topics include: » Wrapping up 2020 discussions » Revisiting the campus master plan » Panel about connections between lib- eral arts education and career opportuni- ties, roles of undergraduate research and internships » Plans to release amount of future tu- ition increases COURTESY OF THE COUNSELING CENTER AND KRISTEN HUFFMAN Lef: Counseling Center staf pose for a group photo inside the newly renovated building. Right: the Counseling Center. Djerassi, a creator 34 percent of students visited the of her freshman year, Young and prescribed an anti-de- went to see a Kenyon coun- pressant medication in the Counseling Center in 2014. selor. “I learned that going spring of 2013, during her of the Pill, dies home was an option, and I sophomore year.