Download or read book Studies Towards the Synthesis of Optically Active Bicyclo 2 2 2 octa 2 5 dienes written by Breeyawn Nycole Lybbert and published by . This book was released on 2012 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optically active 2,5-disubstituted bicyclo[2.2.2]octa-2,5-dienes (bod) have found use within synthetic organic chemistry as chiral ligands for rhodium asymmetric catalysis reactions. These chiral ligands often provide greater enantioselectivity than their phosphorus-based chiral ligand cousins when employed in the formation of carbon-carbon bonds under rhodium catalysis. The drawback to using these types of 2,5-disubstituted bicyclo[2.2.2]octa-2,5-diene ligands is that they are very expensive to buy if they are commercially available or they must be synthesized if they are not commercially available. Present literature syntheses of these bod ligands rely on the physical separation of diastereomeric derivatives via recrystallization with low recovery or the separation of enantiomers via chiral HPLC, in which only small amounts of material may be separated. We have devised a synthesis of phenyl, benzyl, and methyl substituted bod ligands based on a bridged Robinson annulation reaction of 1,5-diketones and 1,5-ketoaldehydes, which gives the bicyclic core necessary for the bod ligand. Furthermore, our synthesis is designed to create optically active 1,5-diketones and 1,5-ketoaldehydes which transfer their chirality to the bicyclic core of the molecule. Our synthesis does not rely upon separation of racemic material at any step; instead we provide a method to synthesize any optically active bod ligand that is desired. We successfully synthesized the chiral 3-allylcyclohexanone (>95% ee), a key intermediate in our synthesis, using a chiral conjugate allylation of & alpha;, & beta;-unsaturated & beta;-ketoesters using Cu(OTf)2 and the chiral tBu-box ligand. We then successfully completed the racemic synthesis of 2,5-diphenylbicyclo[2.2.2]octa-2,5-diene (Ph-bod) over 11 steps in 4.4% yield. The chiral Ph-bod ligand is projected to take 14 steps and proceed in a 1.1% overall yield. We also synthesized the racemic 2,5-bis(phenylmethyl)bicyclo[2.2.2]octa-2,5-diene (Bn-bod) over 7 steps in 1.4% overall yield. The synthesis of 2,5-dimethylbicyclo[2.2.2]ocat-2,5-diene (Me-bod) was attempted but was unsuccessful at this time. Ultimately we proved the utility of the bridged Robinson annulation reaction for the synthesis of various bicyclo[2.2.2]octa-2,5-dienes.
Download or read book Synthesis And Rotatory Dispersion Of Optically Active Bicyclo 2 2 1 Hept 5 En 2 One Bicyclo 2 2 2 Oct 5 En 2 One And 5 Methylenebicyclo 2 2 1 Hept 2 Ene written by Joel Gilbert Berger and published by . This book was released on 1961 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis of Optically Active Bicyclo 2 2 2 octane Derivatives written by Fredrik Almqvist and published by . This book was released on 1996 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Strain and Its Implications in Organic Chemistry written by Armin de Meijere and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: The topic ·Stress and Strain· of this conference was ideally constrasted by the remoteness and quiet atmosphere of the meeting place Hotel Seehof In Ratzeburg, a small medieval town situated on a peninsula in lake "Kuchensee· east of Hamburg In northern Germany. With the participation of 53 leading experts from all over the world, the workshop covered the widest possible range from the advancement of bonding theory, new mechanistic insights into chemical transformations and physical properties of highly strained compounds to their use as building blocks In organic synthesis and even as probes Into the detection of enzyme mechanisms. Because of their specific reactivities small ring units can uniquely play their role in the construction of composite functionalities. Such functionalities can increase the elegance In natural and non-natural products syntheses, since they help to develop more convergent synthetic routes and Improve the necessary chemo-, regio-and stereo-selectivity. This book presents all of the 20 Invited lectures and is complemented with short versions of 12 contributed papers and 13 poster presentations. I am convinced that it will stimulate further rapid development of this field of organic chemistry, which recently has seen extensions into the bioorganic area as well as towards new materials. In fact, several ·supra-natural" -at first sight exotic -compounds are already available In useful quantities and are being exploited to create vastly new molecular devices, i. e. compounds with unprecedented molecular functions and polymers with unconventional properties.
Download or read book Methodologies of Bicyclo 2 2 2 octane Compounds and Progress Toward the Total Synthesis of Parthenolide written by Courtney Arielle Roberts and published by . This book was released on 2016 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: In Chapter 1, rearrangements of 4-substituted bicyclo[2.2.2]oct-2-enyl-5-selenophenyl esters are explored. Reduction of the esters under radical-generating conditions initially generates a bicyclo[2.2.2]oct-5-en-2-yl radical which can rearrange to a bicyclo[3.2.1]oct-6-en-2-yl radical via a cyclopropylcarbinyl radical. Although the bicyclo[3.2.1]octene system exhibits greater strain than does the bicyclo[2.2.2]octene system, radical-stabilizing substituents can reverse this preference. The product ratios are influenced by the interplay of ring strain and radical stability. In addition, the rearranged products favored the equatorial over the axial isomers, which can be explained by torsional steering. In Chapter 2, different approaches to the synthesis of the optically active bicyclo[2.2.2]octane-2,5-diones are presented. A stereoselective Diels-Alder cycloaddition was explored to construct the bicyclo[2.2.2]octane skeleton in an efficient manner. This approach was hindered by unexpected polymerization and lack of stereoselectivity. A different method of synthesizing the optically active bicyclo[2.2.2]octane-2,5-dione featuring a diastereoselective 1,4-addition is also presented. In Chapter 3, progress toward the total synthesis of parthenolide is described. The synthetic route relies on ring-closing metathesis to close the 10-membered carbocycle of the natural product. The efforts leading up to and including the key ring-closing step are described. Specific attention is given to different methods for overcoming the difficulties associated with medium-sized ring formation.
Download or read book Organic Reaction Mechanisms 1987 written by A. C. Knipe and published by John Wiley & Sons. This book was released on 2008-04-30 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt: The only book series to summarize the latest progress on organic reaction mechanisms, Organic Reaction Mechanisms, 1987 surveys the development in understanding of the main classes of organic reaction mechanisms reported in the primary scientific literature in 1987. The 23rd annual volume in this highly successful series highlights mechanisms of stereo-specific reactions. Reviews are compiled by a team of experienced editors and authors, allowing advanced undergraduates, graduate students, postdocs, and chemists to rely on the volume's continuing quality of selection and presentation.
Download or read book The Synthesis of Bicyclo 2 2 1 2 5 heptadiene and Bicyclo 2 2 2 2 5 octadiene and Related Compounds written by John Angus Brown and published by . This book was released on 1954 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book American Doctoral Dissertations written by and published by . This book was released on 1985 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book SYNTHETIC STRATEGY DIRECTED TOWARDS THE SYNTHESIS OF BICYCLO 3 3 0 OCTA 3 5 8 TRIENE 2 7 DIONE written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Although the chemistry of benzenoid and nonbenzenoid quinones have been the subject of extensive theoretical and experimental studies, the extent of our present understanding regarding the geometries and stabilities of quinones of pentalene is meager. After studying the existence of cyclopentadienone and its reactivity as a diene and dienophile in the literature, the study of some related species, particularly the ones with fully unsaturated pentalenic structures were started. In this thesis, the elusive compound bicyclo[3.3.0]octa-3,5,8-triene-2,7-dione was tried to synthesize by using the synthetic strategy which was developed by us. We used cycloheptatriene as the starting material. The bicyclic endoperoxiedes mixture obtained by the photooxygenation of cycloheptatriene was v treated with triethylamine to give tropone in high yield. Selective reduction of tropone afforded cyclohepta-3,5-dione which was converted by the way of photochemistry to the bicyclo[3.2.0]hept-6-en-3-one. After protection of the carbonyl group, dibromocarbene was added to the double bond to give desired bicyclic compound with pentalene skeleton. Substitution of the allylic bromide with hydroxyl group followed by PCC oxidation resulted in the formation of a diketone. All efforts to convert this diketone into fully conjugated system failed.
Download or read book Quarterly Journal of the Chemical Society of London written by Chemical Society (Great Britain) and published by . This book was released on 1971 with total page 1564 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rhodium Catalysis in Organic Synthesis written by Ken Tanaka and published by John Wiley & Sons. This book was released on 2018-12-31 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: An essential reference to the highly effective reactions applied to modern organic synthesis Rhodium complexes are one of the most important transition metals for organic synthesis due to their ability to catalyze a variety of useful transformations. Rhodium Catalysis in Organic Synthesis explores the most recent progress and new developments in the field of catalytic cyclization reactions using rhodium(I) complexes and catalytic carbon-hydrogen bond activation reactions using rhodium(II) and rhodium(III) complexes. Edited by a noted expert in the field with contributions from a panel of leading international scientists, Rhodium Catalysis in Organic Synthesis presents the essential information in one comprehensive volume. Designed to be an accessible resource, the book is arranged by different reaction types. All the chapters provide insight into each transformation and include information on the history, selectivity, scope, mechanism, and application. In addition, the chapters offer a summary and outlook of each transformation. This important resource: -Offers a comprehensive review of how rhodium complexes catalyze a variety of highly useful reactions for organic synthesis (e.g. coupling reactions, CH-bond functionalization, hydroformylation, cyclization reactions and others) -Includes information on the most recent developments that contain a range of new, efficient, elegant, reliable and useful reactions -Presents a volume edited by one of the international leading scientists working in the field today -Contains the information that can be applied by researchers in academia and also professionals in pharmaceutical, agrochemical and fine chemical companies Written for academics and synthetic chemists working with organometallics, Rhodium Catalysis in Organic Synthesis contains the most recent information available on the developments and applications in the field of catalytic cyclization reactions using rhodium complexes.
Download or read book Alicyclic Chemistry Volume 6 written by M. A. McKervey and published by Royal Society of Chemistry. This book was released on 1978 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation. Specialist Periodical Reports provide systematic and detailed review coverage of progress in the major areas of chemical research. Written by experts in their specialist fields the series creates a unique service for the active research chemist, supplying regular critical in-depth accounts of progress in particular areas of chemistry. For over 80 years the Royal Society of Chemistry and its predecessor, the Chemical Society, have been publishing reports charting developments in chemistry, which originally took the form of Annual Reports. However, by 1967 the whole spectrum of chemistry could no longer be contained within one volume and the series Specialist Periodical Reports was born. The Annual Reports themselves still existed but were divided into two, and subsequently three, volumes covering Inorganic, Organic and Physical Chemistry. For more general coverage of the highlights in chemistry they remain a 'must'. Since that time the SPR series has altered according to the fluctuating degree of activity in various fields of chemistry. Some titles have remained unchanged, while others have altered their emphasis along with their titles; some have been combined under a new name whereas others have had to be discontinued.
Download or read book Bibliography of Mass Spectroscopy Literature for 1970 written by and published by . This book was released on 1972 with total page 900 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Alicyclic Chemistry written by M A McKervey and published by Royal Society of Chemistry. This book was released on 2007-10-31 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: Specialist Periodical Reports provide systematic and detailed review coverage of progress in the major areas of chemical research. Written by experts in their specialist fields the series creates a unique service for the active research chemist, supplying regular critical in-depth accounts of progress in particular areas of chemistry. For over 80 years the Royal Society of Chemistry and its predecessor, the Chemical Society, have been publishing reports charting developments in chemistry, which originally took the form of Annual Reports. However, by 1967 the whole spectrum of chemistry could no longer be contained within one volume and the series Specialist Periodical Reports was born. The Annual Reports themselves still existed but were divided into two, and subsequently three, volumes covering Inorganic, Organic and Physical Chemistry. For more general coverage of the highlights in chemistry they remain a 'must'. Since that time the SPR series has altered according to the fluctuating degree of activity in various fields of chemistry. Some titles have remained unchanged, while others have altered their emphasis along with their titles; some have been combined under a new name whereas others have had to be discontinued.
Download or read book A Study of the Synthesis and Properties of Bicyclo 2 2 2 2 5 7 octatriene and Related Compounds written by Jack Hine and published by . This book was released on 1955 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of the Chemical Society written by and published by . This book was released on 1989 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Terpenoids and Steroids written by James R Hanson and published by Royal Society of Chemistry. This book was released on 2007-10-31 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: Specialist Periodical Reports provide systematic and detailed review coverage of progress in the major areas of chemical research. Written by experts in their specialist fields the series creates a unique service for the active research chemist, supplying regular critical in-depth accounts of progress in particular areas of chemistry. For over 90 years The Royal Society of Chemistry and its predecessor, the Chemical Society, have been publishing reports charting developments in chemistry, which originally took the form of Annual Reports. However, by 1967 the whole spectrum of chemistry could no longer be contained within one volume and the series Specialist Periodical Reports was born. The Annual Reports themselves still existed but were divided into two, and subsequently three, volumes covering Inorganic, Organic and Physical Chemistry. For more general coverage of the highlights in chemistry they remain a 'must'. Since that time the SPR series has altered according to the fluctuating degree of activity in various fields of chemistry. Some titles have remained unchanged, while others have altered their emphasis along with their titles; some have been combined under a new name whereas others have had to be discontinued. The current list of Specialist Periodical Reports can be seen on the inside flap of this volume.
