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Academic dissertation to be presented with the assent of the Faculty of Science of the University of Oulu for public defence in Raahensali Auditorium L10 , Linnanmaa, on 21 August , at 12 noon. A , Oulu, Finland. Abstract The synthesis of -hydroxy aldehydes and hydroxymethyl ketones as well as their interconversion to each other are discussed in this thesis.
The literature survey of the monograph reviews the synthetic methods for the preparation of 1,2-bifunctionalized hydroxy aldehydes and ketones. The keto-aldehyde isomerisation reaction catalyzed by Triosephosphate isomerase enzyme TIM and organic compounds that interact with the TIM are also introduced. In addition, the microwave heating techniques in organic syntheses are reviewed.
The practical work consists of two entities: The synthesis of new substrate candidates and transition state analogues for a mutated monomeric TIM. These compounds are model compounds for the catalytic activity and the structural studies of the mutated monomeric TIM. The synthesis of the sulphonyl -hydroxy ketone-based substrate candidates consists of four successive syntheses. The microwave-activation was utilized in the preparation of a carbon-sulphur bond and the synthesis of hydroxymethyl ketones.
The improved synthesis of the terminal -hydroxy ketone functionality with microwave activation is presented. The formation of charged compounds was utilized to improve the absorption of microwave energy of reaction mixtures.
The design and the synthetic work were carried out in accordance to principles of green chemistry. The second part of the practical work is the development of an organocatalytic -oxybenzoylation reaction of aldehydes with high enantiomeric selectivity. This novel method generated enantiomerically pure -hydroxy aldehydes in the stable benzoateprotected form from achiral starting materials under mild conditions at the presence of air and moisture.
Keywords: -hydroxy aldehyde, -hydroxy ketone, microwave-assisted synthesis, organocatalysis, triosephosphate isomerase. Acknowledgements The present study was carried out in the Department of chemistry at the University of Oulu during the years Part of the work was carried out at Cardiff University during my research fellow exchange period on 1.
I respectively thank University of Oulu and Cardiff University for allowing me to use the facilities at the universities.
I would like to express my gratitude to my supervisor Professor Marja Lajunen for the guidance, hart work and the endless support and kindness during the years of my study. This thesis exists because of you. I thank you for the interdisciplinary discussions and ideas throughout the years of our shared project.
I thank Doctor Nicholas Tomkinson for letting me to work in his lab at Cardiff University and for providing me an opportunity to learn the chemistry of organocatalysis. Nick also gave me a new and professional perspective to the organic chemistry. Special thanks go to Doctor Sze Chak Jacky Yau for helping me at the beginning of my exchange period and for carrying out the lab work to our publication after I have left.
I warmly thank past and present members of the Lajunen group. Special thanks go to my co-authors Sanna Yliniemel and Mikko Leskinen for carrying out our syntheses and experiments with such an enthusiasm and accurately. I highly value all the fruitful moments around the round coffee table. I appreciate the excellent work that you carried out at the laboratory of mass spectrometry.
Sincerely thanks also go to the technical staff of the Department of chemistry for keeping up things running. I thank people of the kealase group; Mikko, Markus, Marco, Sampo, Nanna, Silja, Milja and Ritva for the many discussions and work around our shared project. Sitting around the picture of TIM has been remembered moments; especially when a single molecule of own synthesis can be seen on live on the screen. I thank Mikko Salin for his work and discussions, and the help to create those impressive pictures of TIM to my thesis.
Tim, Deb, Paul, Kelly, Michael, and other friends and colleagues in Cardiff; I thank you for making such a friendly and enthusiastic atmosphere in the lab and outside at the city of Cardiff. Lets cheer with a cold pint of Brains. I also thank Lauri Gardner for revising the language.
Finally, I gratefully thank my family for love and support throughout these years. Mom and dad, this book is dedicated to you.
Hanna, I thank you for being as you are. From my heart I thank Anu for endless love and understanding during the years of this thesis. You have given me strength and reason to carry out and to finish this work. Oulu, June List of original articles This thesis is based on the following publications which are referred to in the text by their Roman numerals I.
Z Naturforsch B: Chem Sci 62 10 : Synth Commun 39 11 : Tetrahedron Lett 50 26 : In the summer of , our group linked up with the working consortium of protein crystallographers, biochemists and process engineers. There was an urgent need to model compounds for the study of mutated triosephosphate isomerase ATIM  that could be used to produce new non-natural -hydroxy aldehydes from -hydroxy ketones. With these compounds further information on the triosephosphate isomerase reaction could be gained and furthermore they would help to determine the binding properties and the fine structure of the mutated ATIM enzyme.
There were several reasons to choose TIM as the reference enzyme. It is small in size and a stable biomolecule that does not require co-factors. TIM is also easy to crystallize, highly soluble, easily expressed in Escherichia coli, and the TIMbarrel is a well-known enzyme fold.
For the consortium, the most interesting feature is the TIM-catalyzed reaction where achiral -hydroxy ketone is transformed to an enantiomerically pure R --hydroxy aldehyde. This study focused on the chemistry and the synthesis of two bi-functional compounds: -hydroxy aldehydes 1 and terminal -hydroxy ketones 2, as well as their interconversion into each other Fig.
The keto-aldehyde tautomerism is a It is also known as a Lobry-de Bruyn-van Ekenstein transformation . The -hydroxy aldehydes are highly reactive compounds and contain a stereogenic centre at -carbon, which makes them suitable substances for many biochemical transformations, while -hydroxy ketones are relatively stable and can be readily synthesized and stored for further use. The aim and strategy of the work was to synthesize a library of compounds with an -hydroxy ketone group based on natural substrates of triosephosphate isomerase, and a library of transition state analogues which mimic 2PG and have a chain length of one carbon atom shorter than the ketone.
The work presented in this thesis consists of synthetic chemistry carried out in the laboratory of organic chemistry. The design and computational studies of substrate candidates were conducted in collaboration with the research groups of biochemistry and bioengineering supervised by professors Rik Wierenga and Peter Neubauer, respectively. The ultimate goal of the consortium was to develop a method to convert an hydroxy ketone to an -hydroxy aldehyde.
With the exception of specific reactions of ketones , the synthesis of 1,2-fuctionalized hydroxy ketones utilizes similar synthetic protocols to that of -hydroxy aldehydes.
Often the terminal -hydroxy ketones also are synthesized via tautomerization of -hydroxy aldehyde intermediate .
Because of these reasons, the literature survey of this thesis mainly focuses on synthetic methods, which gives an -hydroxy aldehyde product, even though the isolated product was in some cases an -hydroxy ketone. As a part of the learning process of the synthesis of -hydroxy aldehydes the author visited the research group of Doctor Nicholas Tomkinson at Cardiff University.
The asymmetric organocatalytic -oxybenzoylation of aldehydes appeared eco-friendly, interesting and important to become familiar with. The aim of the study was to develop an asymmetric synthesis of -oxo functionalized Being a part of the development of a synthetic method, which created -hydroxy aldehydes in an asymmetric and rather stable form using a non-toxic recyclable catalyst in the presence of air and moisture, was one of highlights of the PhD study.
The results from the annual KETJU seminar organised by the Academy of Finland in were the emphasis of the importance of inventing a new method of synthesis for -hydroxy aldehydes and the need to create more environmentally benign one-carbon synthons for homologation reactions. At the beginning of this research project, there were two important aspects in modern synthetic chemistry, which our group was focused on: the concept of green chemistry and synthetic applications using a microwave heating technique.
The philosophy of the design, selection and carrying out chemical synthesis were the twelve principles of green chemistry . Green chemistry includes the following precepts: the unnecessary production of chemical waste and the level of its toxicity should be considered and whenever possible minimised. Reactions should be designed in such a way that most of the materials used in syntheses are included into the final product.
The toxicity and the environmental impact of the reagents and final products should be low. Wasteful isolation and purification processes should be made less necessary. Energy requirements need to be considered. Bulk chemicals should be readily accessible and preferably renewable. Respectively renewable catalytic processes are better than stoichiometric reactions. Chemical transformations should be easy to monitor and control from the beginning to the end of the reaction.
The risk of hazards, chemical accidents and leaks to the environmental should be minimized. Organocatalysis  as well as biocatalysis  would provide a solution to this. At their best, catalysis will happen with a quantitative conversion and high selectivity in water at ambient temperature creating no toxic waste. Microwave-assisted organic synthesis  can be considered as one way of improving the syntheses or as a concrete application to improve energy efficiency and to decrease the time of the chemical transformation.
The synthesis and applications of -hydroxy aldehydes and their synthetic equivalents. The main product of the reaction of triosephosphate isomerase is an -hydroxy aldehyde. Thus the exclusive study of -hydroxy aldehydes and their synthetic equivalents was deemed necessary in order to build a better understanding of this product.
How would it act in different conditions, how it could be isolated, or protected in situ, or if nothing else, analysed and determined thoroughly. The -hydroxy aldehydes and their synthetic equivalents are an interesting subject from the synthetic point of view.
They are valuable synthetic intermediates and building blocks for the synthesis of carbohydrates and analogues via chemical or enzymatic aldol reaction. The -hydroxy carbonyl compounds are structural subunits of natural products including sugars and -hydroxy--amino acids .
The synthesis of -hydroxy aldehydes can be summarized in five main routes Fig. Firstly, the selective oxidation of primary alcohol 3 provides the hydroxy aldehyde functionality. Thirdly, formulation of carbonyl compounds using an anion derived from hetero disubstituted carbanions 5 as a formyl anion equivalent gives -hydroxy aldehyde The fourth common method is the -hydroxylation of aldehyde or their enol, which is nowadays widely utilized in organocatalytic reactions.
Alternatively, -hydroxy aldehyde equivalents are obtained, either by the ring opening of a 2,3-epoxy-acetal 6 by various nucleophiles or by substitution of metal halide compounds. Therefore, the last step in their synthesis has to be efficient and should not generate by-products that need laborious separation.
Often reactions have been continued further directly from the nonisolated reaction media containing hydroxy aldehydes or its synthetic equivalents. The protection of the -hydroxyl group with a bulky substituent or the acetalisation of the free aldehyde functionality can in some cases be used to stabilize the forming product.
Novel methods on the preparation of enantiomerically pure -hydroxy aldehydes consist of transformations with enzymes, as well as chiral auxiliaries, or chiral starting materials .
REAKSI PADA ALKOHOL, ETER, ALDEHID, KETON, ASAM ...
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Jurnal Aldehid dan Keton
Academic dissertation to be presented with the assent of the Faculty of Science of the University of Oulu for public defence in Raahensali Auditorium L10 , Linnanmaa, on 21 August , at 12 noon. A , Oulu, Finland. Abstract The synthesis of -hydroxy aldehydes and hydroxymethyl ketones as well as their interconversion to each other are discussed in this thesis. The literature survey of the monograph reviews the synthetic methods for the preparation of 1,2-bifunctionalized hydroxy aldehydes and ketones. The keto-aldehyde isomerisation reaction catalyzed by Triosephosphate isomerase enzyme TIM and organic compounds that interact with the TIM are also introduced. In addition, the microwave heating techniques in organic syntheses are reviewed. The practical work consists of two entities: The synthesis of new substrate candidates and transition state analogues for a mutated monomeric TIM.
Jurnal Aldehid Dan Keton
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