Oxidations to Carbonyl
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
United States Patent (19) (11) 4,055,601 Ehmann 45) Oct
United States Patent (19) (11) 4,055,601 Ehmann 45) Oct. 25, 1977 (54) PROCESS FOR THE OXDATION OF PRIMARY ALLYLCALCOHOLS OTHER PUBLICATIONS Djerassi, "Organic Reactions', vol. VI, chapt. 5, pp. 75 Inventor: William J. Ehmann, Orange Park, 207-234. Fla. Adkins, et al., "J. Amer. Chem. Soc.' vol. 71, pp. (73) Assignee: SCM Corporation, New York, N.Y. 3622-3629. Batty et al., "Chem. Society Journal' (1938), pp. 21 Appl. No.: 582,114 175-179. Filed: May 30, 1975 22 Primary Examiner-Bernard Helfin Related U.S. Application Data Attorney, Agent, or Firm-Richard H. Thomas 63) Continuation-in-part of Ser. No. 437,188, Jan. 28, 1974, 57 ABSTRACT abandoned. Improved conversions of 3-substituted and 3,3-disub (51) Int. Cl’.............................................. CO7C 45/16 stituted allyl alcohols to the corresponding aldehydes (52) U.S. C. ............................ 260/593 R, 260/603 C, are obtained in an Oppenauer oxidation process, under 260/347.8; 260/599; 260/600 R; 260/598 Oppenauer oxidation conditions, by carrying out the (58) Field of Search ............ 260/603 HF, 599, 603 C, oxidation employing furfural as the hydrogen acceptor. 260/593 R, 600 R, 598 The invention is particularly applicable to the oxidation of geraniol and nerol to citral, which can be converted (56) References Cited directly to pseudoionone without purification. U.S. PATENT DOCUMENTS 2,801,266 7/1957 Schinz ........................... 260/603 HF 13 Claims, No Drawings 4,055,601 1. tion produces water as a by-product which hydrolyzes PROCESS FOR THE OXDATION OF PRIMARY and consumes the aluminum catalyst. This requires ALLYLCALCOHOLS nearly stoichiometric quantities (as compared to cata lytic quantities) of the aluminum catalyst (notice page This application is a continuation-in-part of prior 224 of Djerassi, supra). -
Oxidation of Secondary Alcohols to Ketones
Oxidation of secondary alcohols to ketones The oxidation of secondary alcohols to ketones is an important oxidation reaction in organic chemistry. Where a secondary alcohol is oxidised, it is converted to a ketone. The hydrogen from the hydroxyl group is lost along with the hydrogen bonded to the second carbon. The remaining oxygen then forms double bonds with the carbon. This leaves a ketone, as R1–COR2. Ketones cannot normally be oxidised any further because this would involve breaking a C–C bond, which requires too much energy.[1] The reaction can occur using a variety of oxidants. Contents Potassium dichromate PCC (Pyridinium chlorochromate) Dess–Martin oxidation Swern oxidation Oppenauer oxidation Fétizon oxidation See also References Potassium dichromate A secondary alcohol can be oxidised into a ketone using acidified potassium dichromate and heating under 2− 3+ reflux. The orange-red dichromate ion, Cr2O7 , is reduced to the green Cr ion. This reaction was once used in an alcohol breath test. PCC (Pyridinium chlorochromate) PCC, when used in an organic solvent, can be used to oxidise a secondary alcohol into a ketone. It has the advantage of doing so selectively without the tendency to over-oxidise. Dess–Martin oxidation The Dess–Martin periodinane is a mild oxidant for the conversion of alcohols to aldehydes or ketones.[2] The reaction is performed under standard conditions, at room temperature, most often in dichloromethane. The reaction takes between half an hour and two hours to complete. The product is then separated from the spent periodinane.[3] Swern oxidation Swern oxidation oxidises secondary alcohols into ketones using oxalyl chloride and dimethylsulfoxide. -
Alcohol Oxidation
Alcohol oxidation Alcohol oxidation is an important organic reaction. Primary alcohols (R-CH2-OH) can be oxidized either Mechanism of oxidation of primary alcohols to carboxylic acids via aldehydes and The indirect oxidation of aldehyde hydrates primary alcohols to carboxylic acids normally proceeds via the corresponding aldehyde, which is transformed via an aldehyde hydrate (R- CH(OH)2) by reaction with water. The oxidation of a primary alcohol at the aldehyde level is possible by performing the reaction in absence of water, so that no aldehyde hydrate can be formed. Contents Oxidation to aldehydes Oxidation to ketones Oxidation to carboxylic acids Diol oxidation References Oxidation to aldehydes Oxidation of alcohols to aldehydes is partial oxidation; aldehydes are further oxidized to carboxylic acids. Conditions required for making aldehydes are heat and distillation. In aldehyde formation, the temperature of the reaction should be kept above the boiling point of the aldehyde and below the boiling point of the alcohol. Reagents useful for the transformation of primary alcohols to aldehydes are normally also suitable for the oxidation of secondary alcohols to ketones. These include: Oxidation of alcohols to aldehydes and ketones Chromium-based reagents, such as Collins reagent (CrO3·Py2), PDC or PCC. Sulfonium species known as "activated DMSO" which can result from reaction of DMSO with electrophiles, such as oxalyl chloride (Swern oxidation), a carbodiimide (Pfitzner-Moffatt oxidation) or the complex SO3·Py (Parikh-Doering oxidation). Hypervalent iodine compounds, such as Dess-Martin periodinane or 2-Iodoxybenzoic acid. Catalytic TPAP in presence of excess of NMO (Ley oxidation). Catalytic TEMPO in presence of excess bleach (NaOCl) (Oxoammonium-catalyzed oxidation). -
20 More About Oxidation–Reduction Reactions
More About 20 Oxidation–Reduction Reactions OOC n important group of organic reactions consists of those that O A involve the transfer of electrons C from one molecule to another. Organic chemists H OH use these reactions—called oxidation–reduction reactions or redox reactions—to synthesize a large O variety of compounds. Redox reactions are also important C in biological systems because many of these reactions produce HH energy. You have seen a number of oxidation and reduction reactions in other chapters, but discussing them as a group will give you the opportunity to CH3OH compare them. In an oxidation–reduction reaction, one compound loses electrons and one com- pound gains electrons. The compound that loses electrons is oxidized, and the one that gains electrons is reduced. One way to remember the difference between oxidation and reduction is with the phrase “LEO the lion says GER”: Loss of Electrons is Oxi- dation; Gain of Electrons is Reduction. The following is an example of an oxidation–reduction reaction involving inorganic reagents: Cu+ + Fe3+ ¡ Cu2+ + Fe2+ In this reaction,Cu+ loses an electron, so Cu+ is oxidized. Fe3+ gains an electron, so Fe3+ is reduced. The reaction demonstrates two important points about oxidation– reduction reactions. First, oxidation is always coupled with reduction. In other words, a compound cannot gain electrons (be reduced) unless another compound in the reaction simultaneously loses electrons (is oxidized). Second, the compound that is oxidized (Cu+) is called the reducing agent because it loses the electrons that are used to reduce the other compound (Fe3+). Similarly, the compound that is reduced (Fe3+) is called the oxidizing agent because it gains the electrons given up by the other compound (Cu+) when it is oxidized. -
Asymmetric Total Synthesis of Congeners of Hydramycin, an Anthraquinone-Type Antitumor Agent
University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Doctoral Dissertations Graduate School 12-2011 Asymmetric Total Synthesis of Congeners of Hydramycin, an Anthraquinone-Type Antitumor Agent Costyl Ngnouomeuchi Njiojob [email protected] Follow this and additional works at: https://trace.tennessee.edu/utk_graddiss Part of the Heterocyclic Compounds Commons, Organic Chemicals Commons, and the Polycyclic Compounds Commons Recommended Citation Njiojob, Costyl Ngnouomeuchi, "Asymmetric Total Synthesis of Congeners of Hydramycin, an Anthraquinone-Type Antitumor Agent. " PhD diss., University of Tennessee, 2011. https://trace.tennessee.edu/utk_graddiss/1210 This Dissertation is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a dissertation written by Costyl Ngnouomeuchi Njiojob entitled "Asymmetric Total Synthesis of Congeners of Hydramycin, an Anthraquinone-Type Antitumor Agent." I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the equirr ements for the degree of Doctor of Philosophy, with a major in Chemistry. David C. Baker, Major Professor We have read this dissertation and recommend its acceptance: Shawn Campagna, Ben Xue, Elizabeth Howell Accepted for the Council: Carolyn R. Hodges Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) Asymmetric Total Synthesis of Congeners of Hydramycin, an Anthraquinone-Type Antitumor Agent A Dissertation Presented for the Doctor of Philosophy Degree The University of Tennessee, Knoxville Costyl Ngnouomeuchi Njiojob December 2011 DEDICATION This dissertation is dedicated to my Parents Francois Ngnouomeuchi and Lydie T. -
Short-Step Synthesis of Chenodiol from Stigmasterol
Biosci. Biotechnol. Biochem., 68 (6), 1332–1337, 2004 Short-step Synthesis of Chenodiol from Stigmasterol y Toru UEKAWA, Ken ISHIGAMI, and Takeshi KITAHARA Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan Received February 3, 2004; Accepted March 11, 2004 Chenodiol is an important bile acid widely used for the hydroxyl group (C-3 position), 2) construction of gallstone dissolution and cholestatic liver diseases. We cis-fused rings by hydrogenation (C-5 position), 3) succeeded in a short-step synthesis of chenodiol, starting allylic oxidation and stereoselective reduction (C-7 from the safer phytosterol, stigmasterol. position), and 4) ozonolysis of the side chain and subsequent transformation, including the Wittig reac- Key words: chenodiol; stigmasterol; gallstone dissolu- tion. tion; bovine spongiform encephalopathy Our first synthetic route is outlined in Scheme 2. The hydroxyl group of stigmasterol (2) was inverted by Chenodiol is an important bile acid contained in many mesylation4,5) and the subsequent treatment with cesium vertebrates. This compound is widely used in clinical acetate.6) Inversion under Mitsunobu conditions gave a applications for the dissolution of cholesterol gallstones diastereomixture at the C-3 position, and elimination of and cholestatic liver diseases.1) At present, chenodiol is the hydroxyl group was also observed. Allylic oxidation industrially synthesized from cholic acid,2,3) a major of the C-7 position was accomplished by N-hydroxy- component of bovine bile. BSE (bovine spongiform phthalimide-catalyzed air oxidation, using benzoyl per- encephalopathy) has recently become a global problem oxide as a radical initiator.7,8) The resulting hydroper- and it is now prohibited to use the specified bovine risk oxide was dehydrated to give enone 4. -
Oxidation States of Carbon Oxidation and Reduction in Biology
Oxidation States of Carbon • Addition of H (or “H-”) Reduction 2 • Loss of O2 or O H R H H carboxylic aldehyde alcohol alkane acid (or ketone) • Loss of H 2 Oxidation • Addition of O2 or O + Neither oxidation nor reduction: Addition or loss of H , H2O, or HX Oxidation and Reduction in Biology • Addition of H (or “H-”) Reduction 2 • Loss of O2 or O + h, in plants H OH carbon dioxide e.gg,g., glucose H O 4 C-O bonds per C HO 1 C-O bond per C 0 C-H bond per C HO OH 1 C-H bond per C H OH H H +O+ O2, in animals • Loss of H 2 Oxidation • Addition of O2 or O + Neither oxidation nor reduction: Addition or loss of H , H2O, or HX Biological Oxidation Gone Wrong component of glue alcohol 2 NAD+ dehydrogenase 2 NADH gamma-hydroxybutyrate (GHB, an intoxicant/ date rape drug) Dr. Kevin Carpenter, biochemical geneticist (specialist in pediatric metabolic disorders), Children’s Hospital at Westmead (Sydney), Australia. Behind him: The Agilent GC/MS New York Times, Nov. 8, 2007 used to analyze the Aqua Dots. “Sleuthing for Danger in Toy Beads” Hydrides as Reducing Agents Lithium aluminum hydride (LiAlH4) is a strong reducing agent. It will reduce any C=O containing functional group to an alcohol. + 2. H3O 1. LiAlH4 (or just H2O) carboxylic acid primary alcohol andthd then ano ther equivalent adds, unavoidably. One Reduced by LiAlH : equivalent of 4 H- adds, aldehyde ketone carboxylic ester acyl halide amide acid Hydrides as Reducing Agents Sodium borohydride (NaBH4) is a mild reducing agent. -
Transfer Hydrogenations and Kinetic Resolutions Van Dirk Klomp
transferhydrogenations and kineticresolutions DirkKlomp transferhydrogenationsandkineticresolutions DirkKlomp Uitnodiging voorhetbijwonenvande openbareverdedigingvan hetproefschriften destellingenop maandag 13maart2006 13.00uur endedaaraan voorafgaandetoelichting voorniet-chemiciom 12.30uur indeSenaatszaalvande TechnischeUniversiteitDelft Mekelweg5teDelft Naafloopvande plechtigheidbentuookvan hartewelkomopdereceptie inhetzelfdegebouw. DirkKlomp Esdoornlaan32 1521EBWormerveer 075-6223403 [email protected] Stellingen behorende bij het proefschrift transfer hydrogenations and kinetic resolutions van Dirk Klomp 1- De door Kao et al. gebruikte structuurbepalende verbinding fructose voor de synthese van de mesoporeuze silica SBA-1 bepaalt niet de structuur van het materiaal. H.-M. Kao, C.-C. Ting, A. S. T. Chiang, C.-C. Teng, C.-H. Chen, Chem. Commun. 2005 ,1058-1060. 2- Het door Kim et al. gesuggereerde mechanisme voor de deactivering van het enzym α-CT in de hydrolyse van β-lactonen, waarbij het lacton opent op de 4-positie, is zeer onwaarschijnlijk. D. H. Kim, J. Park, S. J. Chung, J. D. Park, N.-K. Park, J. H. Han, Bioorg. Med. Chem. 2002 , 10 , 2553-2560. 3- Psychologisch gezien betekent de omschakeling door wetenschappelijke tijdschriften van papieren versies naar elektronische, een verlies aan kennis voor de wetenschapper. 4- Omdat de aarde langzamer gaat draaien is soms de toevoeging van schrikkelsecondes noodzakelijk. Wetenschappers die deze secondes pas willen toevoegen op het moment dat ze zijn opgespaard tot een schrikkeluur, omdat de toevoegingen storingen kunnen veroorzaken in elektronische apparatuur, hebben de menselijke factor uit het oog verloren. 5- In de weekeindes waarin een nieuw boek over Harry Potter uitkomt, is het aantal kinderen dat op de eerstehulpafdeling van het ziekenhuis belandt bijna half zo groot als in andere weekeindes. Gwilym et al. hebben de afname over de lange termijn waarschijnlijk onderschat. -
Chromic Acid Oxidation of Hydrocarbons at The
CHROMIC ACID OXIDATION OF HYDROCARBONS AT THE BENZYLIC POSITION USING THE JONES REAGENT AND C-13 NMR STUDIES OF GEM-DIMETHYL INDANS AND -INDANONES By Radhika Rangarajan Ii Bachelor of Science Annamalai University Annamalai Nagar, India 1979 Submitted to the Faculty of the Graduate College of the Oklahoma State University in partial fulfillment of the requirements for the Degree of DOCTOR OF PHILOSOPHY December, 1984 1hes\s )ti84 D ~ \°' U,£!- c.o p, ~ BENZYLIC POSITION USING THE JONES REAGENT AND C-13 NMR STUDY OF GEM-DIMTHYL INDANS AND -INDANONES Thesis Approved: (] . Dean of the Graduate College ii 1218538 •t ACKNOWLEDGMENTS I wish to begin with expressing my whole-hearted gratitude to Dr. E. J. Eisenbraun for his care and guidance during the course of this research. My committee members Dr. R. A. Bunce, Dr. E. M. Holt and Dr. E. C. Nelson have been very helpful in carefully evaluating this work. I appreciate all their help. I would like to thank Dr. T. Rangarajan, Dr. Pourahmady, Mr. Stan Sigle and Mr. Norm Perreira, who played an important role in this investigation. I acknowledge the financial support provided by the Oklahoma State University, Department of Chemistry, Department of Energy and Dow Chemical Company during my graduate tenure. I extend my deepest appreciation to my parents, Rangarajan and Shantha Rangarajan, without whose encouragement this study would not have been possible. A special thanks is due to Mrs. Lisa Thompson for typing my manuscript. iii TABLE OF CONTENTS Chapter Page I. INTRODUCTION AND HISTORICAL. 1 II. RESULTS AND DISCUSSION •• . 15 General •••••• . 15 Oxidation of Hydrocarbons •••••••• 19 Estimation of Solvent Consumption. -
Still More Carbonyl Chemistry
Lecture 17 Still More Carbonyl Chemistry March 26, 2019 Chemistry 328N Second Midterm Exam ⚫ When: Tomorrow, Wednesday, 3/27 ⚫ When: 7-9 PM (please do not be late) ⚫ Where: Painter 3.02!!! ⚫ What: Covers through last Thursday’s lecture ⚫ Remember: Homework problems!! ⚫ Please…bring pencils and an eraser no calculator and no phones …….Do a good job!!! Chemistry 328N Early Exam ⚫ Authorized students with exam conflict ⚫ When: 5-7 PM Tomorrow, 3/27 ⚫ Where: ETC 2.136 ⚫ Pencil and eraser no calculator and no phone ⚫ You must stay in the exam room until 7 PM Chemistry 328N Chromic Acid Oxidations Chemistry 328N Chemistry 328N Erin Brokovich ⚫ Hexavalent chromium compounds (including chromium trioxide, chromic acids, chromates, chlorochromates) are toxic and carcinogenic. Chemistry 328N Oxidation at Benzylic Positions O H H C OH H2SO4, K2CrO4 Heat KMnO4 in Base also works Chemistry 328N Selective Chromate Oxidations ⚫ Chromic acid and heat Oxidizes benzylic positions bearing at least one hydrogen to acids ⚫ Jones Reagent (H2CrO4 in acetone) takes primary alcohols to acids and secondary alcohols to ketones…The acetone keeps the reaction cool. Jones oxidation does not oxidize benzylic positions even with a hydrogen. ⚫ PCC (pyridinium chlorochromate) is weaker yet, it only oxidizes primary alcohols to aldehydes (!) and seconday alcohols to ketones. Chemistry 328N The Jones Oxidation Examples H2 SO4 H2 CrO4, Acetone OH OH O O O C C H2SO4 H OH H 2CrO4,Acetone H3C H3C OH O H2 CrO4, Acetone Chemistry 328N PCC Oxidations C5H5N + HCl + CrO3 → [C5H5NH][CrO3Cl] -
215 F12-Notes-Ch 13
Chem 215 F12-Notes – Dr. Masato Koreeda - Page 1 of 13 Date: September 10, 2012 Chapter 13. Alcohols, Diols, and Ethers Overview: Chemistry and reactions of sp3 oxygen groups, particularly oxidation of an alcohol, ether formation, and reactions of oxirane (epoxide) groups. I. What are alcohols, phenols, and ethers? IUPAC names Common names Alcohols (R-OH) Primary alcohols CH3OH methanol methyl alcohol (1°-alcohols) CH3CH2OH ethanol ethyl alcohol pKa ~16-17 CH3CH2CH2OH 1-propanol n-propyl alcohol H3C C CH2OH 2-methyl-1-propanol isobutyl alcohol H3C H H3C C CH2OH 2,2-dimethyl-1-propanol neopentyl alcohol H3C CH3 H C Secondary alcohols 3 C OH 2-propanol isopropyl alcohol (2°-alcohols) H3C H pKa ~17-18 H C-CH 3 2 C OH 2-butanol sec-butyl alcohol H3C H Tertiary alcohols H3C C OH 2-methyl-2-propanol tert-butyl alcohol (3°-alcohols) H3C CH pKa ~19 3 Phenols (Ph-OH) pKa ~10-12 diethyl ether Ethers (R-O-R') CH3CH2-O-CH2CH3 Ph-O-CH=CH2 phenyl vinyl ether RO-: alkoxy CH3O methoxy CH3CH2O ethoxy ArO-: aryloxy PhO phenoxy II. Oxidation Oxidation – historical use of the term: (1) oxide (oxyd/oxyde) – the ‘acid’ form of an element; e.g., S + air → oxide of S (acid of sulfur) (2) oxidation or oxidize – to make such an acid, to make the oxide (3) oxygen – Lavoisier: substance in the air that makes acids; “the bringer of acids” = “oxygen” (4) oxidation or oxidize – to increase the % oxygen in a substance (reduction: to reduce the % oxygen) More modern definition: oxidation or oxidize – loss of electrons (coupled with reduction as gain of electrons) Note: The loss of electrons (oxidation) by one atom or compound must be matched by the gain of electrons (reduction) by another. -
Efforts Towards the Total Synthesis of Azaspiracid-3 DISSERTATION
Efforts towards the Total Synthesis of Azaspiracid-3 DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Zhigao Zhang Graduate Program in Chemistry The Ohio State University 2013 Dissertation Committee: Dr. Craig J. Forsyth, Advisor Dr. Jon R. Parquette Dr Anita E. Mattson Copyright by Zhigao Zhang 2013 Abstract Azaspiracid, a structurally complex marine toxin isolated from the mussel Mytilus edulis in Killary Harbor, Ireland, represents a new class of marine metabolites unrelated to any previous known agent of diarrhetic shellfish posioning. As such, the natural product has spurred considerable interest among organic community. The thesis details the study towards the total synthesis of azaspiracid-3. The C1-C21 domain and C22-C40 domain have been synthesized, which aims to assemble the molecule through Yamaguchi esterification. The ABCD domain involved an efficient NHK coupling reaction between C1-C12 segment and C13-C22 segment. The trioxadispiroketal skeleton was constructed under the influence of acid catalysis. The EFGHI domain highlighted a chelate controlled Mukaiyama aldol reaction to produce C22-C40 linear precursor, and a DIHMA process to assemble the bridged ketal. With the recognition of bridged ketal and spiroaminal functionality in the FGHI domain, the gold-catalysis to achieve these moieties has been proposed. A novel gold- catalyzed spiroaminal formation has been systemically developed. The gold-catalyzed ketallization was then successfully implemented to construct the bridged ketal, while an inevitable elimination could not deliver the desired spiroaminal under gold conditions. A NHK reaction to couple the C1-C21 and C22-C40 domains has also been proposed.