DOCSLIB.ORG

Ethyl Acetoacetate

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Ethyl Acetoacetate 21.6 The Acetoacetic Ester Synthesis Acetoacetic Ester O O C C H3C C OCH2CH3 H H Acetoacetic ester is another name for ethyl acetoacetate. The "acetoacetic ester synthesis" uses acetoacetic ester as a reactant for the preparation of ketones. Deprotonation of Ethyl Acetoacetate O O – C C + CH3CH2O H3C C OCH2CH3 H H Ethyl acetoacetate pKa ~ 11 can be converted readily to its anion with bases such as sodium ethoxide. Deprotonation of Ethyl Acetoacetate O O – C C + CH3CH2O H3C C OCH2CH3 H H Ethyl acetoacetate pKa ~ 11 can be converted readily to its anion K ~ 105 K ~ 10 with bases such as O O sodium ethoxide. C •• C + CH3CH2OH H3C –C OCH2CH3 3 2 H pKa ~ 16 Alkylation of Ethyl Acetoacetate O O The anion of ethyl C •• C acetoacetate can be H C C OCH CH 3 – C OCH2CH3 alkylated using an H alkyl halide (SN2: primary and R X secondary alkyl halides work best; tertiary alkyl halides undergo elimination). Alkylation of Ethyl Acetoacetate O O The anion of ethyl C •• C acetoacetate can be H C C OCH CH 3 – C OCH2CH3 alkylated using an H alkyl halide (SN2: primary and R X secondary alkyl O O halides work best; tertiary alkyl halides C C undergo elimination). H3C C OCH2CH3 H R Conversion to Ketone O O Saponification and C C acidification convert H3C C OH the alkylated H R derivative to the – 1. HO , H2O corresponding b-keto 2. H+ acid. O O The b-keto acid then undergoes C C decarboxylation to H C 3 C OCH2CH3 form a ketone. H R Conversion to Ketone O O Saponification and C C acidification convert H3C C OH the alkylated H R derivative to the corresponding b-keto acid. O The b-keto acid then undergoes decarboxylation to C + CO2 decarboxylation to H3C CH2R form a ketone. Example O O CH3CCH2COCH2CH3 1. NaOCH2CH3 2. CH3CH2CH2CH2Br Example O O CH3CCH2COCH2CH3 1. NaOCH2CH3 2. CH3CH2CH2CH2Br O O CH3CCHCOCH2CH3 CH2CH2CH2CH3 (70%) Example O (60%) CH3CCH2CH2CH2CH2CH3 (60%) 1. NaOH, H2O 2. H+ 3. heat, -CO2 O O CH3CCHCOCH2CH3 CH2CH2CH2CH3 Example: O O Dialkylation CH3CCHCOCH2CH3 CH2CH CH2 Example: O O Dialkylation CH3CCHCOCH2CH3 CH2CH CH2 1. NaOCH2CH3 2. CH3CH2I O O CH3CCCOCH2CH3 CH3CH2 CH2CH CH2 (75%) Example: O Dialkylation CH3CCH CH2CH CH2 CH3CH2 1. NaOH, H2O 2. H+ 3. heat, -CO2 O O CH3CCCOCH2CH3 CH3CH2 CH2CH CH2 Another O Example O COCH2CH3 H b-Keto esters other than ethyl acetoacetate may be used. Another O Example O COCH2CH3 H 1. NaOCH2CH3 2. H2C CHCH2Br O O COCH2CH3 (89%) CH2CH CH2 Another Example O O COCH2CH3 CH2CH CH2 Another Example O H CH2CH CH2 (66%) 1. NaOH, H2O 2. H+ 3. heat, -CO2 O O COCH2CH3 CH2CH CH2 21.7 The Malonic Ester Synthesis Malonic Ester O O C C CH3CH2O C OCH2CH3 H H Malonic ester is another name for diethyl malonate. The "malonic ester synthesis" uses diethyl malonate as a reactant for the preparation of carboxylic acids. An Analogy O O O O CH3CCH2COCH2CH3 CH3CH2OCCH2COCH2CH3 O O CH3CCH2R HOCCH2R The same procedure by which ethyl acetoacetate is used to prepare ketones converts diethyl malonate to carboxylic acids. Example O O CH3CH2OCCH2COCH2CH3 1. NaOCH2CH3 2. H2C CHCH2CH2CH2Br O O CH3CH2OCCHCOCH2CH3 CH2CH2CH2CH CH2 (85%) Example O HOCCH2CH2CH2CH2CH CH2 (75%) 1. NaOH, H2O 2. H+ 3. heat, -CO2 O O CH3CH2OCCHCOCH2CH3 CH2CH2CH2CH CH2 Dialkylation O O CH3CH2OCCH2COCH2CH3 1. NaOCH2CH3 2. CH3Br O O CH3CH2OCCHCOCH2CH3 (79-83%) CH3 Dialkylation O O CH3CH2OCCCOCH2CH3 CH3(CH2)8CH2 CH3 1. NaOCH2CH3 2. CH3(CH2)8CH2Br O O CH3CH2OCCHCOCH2CH3 CH3 Dialkylation O O CH3CH2OCCCOCH2CH3 CH3(CH2)8CH2 CH3 1. NaOH, H2O 2. H+ 3. heat, -CO2 O CH3(CH2)8CH2CHCOH (61-74%) CH3 Another Example O O CH3CH2OCCH2COCH2CH3 1. NaOCH2CH3 2. BrCH2CH2CH2Br O O CH3CH2OCCHCOCH2CH3 CH2CH2CH2Br Another Example This product is not isolated, but cyclizes in the presence of sodium ethoxide. O O CH3CH2OCCHCOCH2CH3 CH2CH2CH2Br O Another O Example CH3CH2OCCCOCH2CH3 H2C CH2 (60-65%) C H2 NaOCH2CH3 O O CH3CH2OCCHCOCH2CH3 CH2CH2CH2Br Another O O Example CH3CH2OCCCOCH2CH3 H2C CH2 C H2 1. NaOH, H2O 2. H+ 3. heat, -CO2 H CO2H C H2C CH2 (80%) C H2.
Load more

Recommended publications
  • 2-Adamantylacetic Acid* B
    CROATICA CHEM1CA ACTA CcACAA 48 (2) I69-i78 (1976) YU ISSN 0011-1643 CCA-927 547.466:542.91 Originai Scientific Paper Synthesis of a-Amino-1-Adamantylacetic and a-Amino­ -2-Adamantylacetic Acid* B . Gaspert, S. Hromadko, and B. Vranesic Research Department »Piiva«, Pharmaceuticai and Chemicai Works, Zagreb, Croatia, Yugosiavia Rece ived September 29 , 1975 a-Amino-2-adamantylacetic acid (VII) was obtained when 2-adamantylcyanoacetylhydrazide (IX) was subjected to Curtius rearrangement or 2-(2-adaman;tyl)-malonamic acid (XII) to Hof­ mann degradation. The same amino acid was obtained when ri.­ -bromo-2-adamantylacetic acid (VI) was •treated with ammonia. Partial hydrolysis of diethyl adamantyl-(1)-malonate (XIV) yie1ded ethyl adamantyl-(1)-malcmate (XV) which, after treatment with thionyl chlodde and then ammonia, gave 2-(1-adamantyl)­ -malonamic acid ethyl ester (XVII). Hofmann degradation of 2-(1 -adamantyl)-malonamic acid ethyl ester gave a-amino-1- -adama:ntylacetic acid (XVIII). Discovery of interesting biological properties of 1-aminoadamantane hy­ drochloride' ·stimulated the synthesis of a large number of structurally related compounds. The synthesis of amino acids, having an adamantyl group as a part of the 2 molecule, has been reported for 3-aminoadamantane-1-carboxyHc acid , a­ -amino-1-adamantylacetic acid3 and recently for 2-'aminoadamantane-2-car­ boxylic acid4. It seemed appmpriate to us to synthetise a-amLno-2-adamantyl­ acetic acid5 and to elaborate a moire convenient synthesis of a-amino-1-ada­ ma:ntylacetic acid6, which
    [Show full text]
  • Synthesis of 3-Fluorooxindole Derivatives Using Diethyl 2-Fluoromalonate
    Durham E-Theses Synthesis of 3-uoro-oxindoles and phenyl uoroacetic acid derivatives HARSANYI, ANTAL How to cite: HARSANYI, ANTAL (2013) Synthesis of 3-uoro-oxindoles and phenyl uoroacetic acid derivatives, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/6357/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk A Thesis Entitled Synthesis of 3-fluoro-oxindoles and phenyl fluoroacetic acid derivatives Submitted by Antal Harsanyi BSc (College of St. Hild and St. Bede) Department of Chemistry A Candidate for the Degree of Master of Science 2012 Declaration The work presented within this thesis was carried out at Durham University between October 2011 and August 2012. This thesis is the work of the author, except where acknowledged by reference and has not been submitted for any other degree. Part of this work has been presented at: 12th RSC Annual Fluorine Group Meeting, St Andrews, August 2012 Statement of copyright The copyright of this thesis rests with the author.
    [Show full text]
  • The Development and Application of Metal-Catalyzed Processes for Organic Synthesis
    The Development and Application of Metal-Catalyzed Processes for Organic Synthesis by Edward J. Hennessy B.A. Chemistry Northwestern University, 2000 Submitted to the Department of Chemistry in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY IN ORGANIC CHEMISTRY at the Massachusetts Institute of Technology June 2005 © 2005 Massachusetts Institute of Technology All Rights Reserved Signature of Author: " - - 1_"' .Da-uirnt of Chemistry May 19, 2005 Certified by: Stephen L. Buchwald Camille Dreyfus Professor of Chemistry Thesis Supervisor Accepted by: Robert W. Field Chairman, Departmental Committee on Graduate Students ARCHIVES: This doctoral thesis has been examined by a committee of the Department of Chemistry as follows: -/ Professor Gregory C. Fu: " Ch Chair Professor Stephen L. Buchwald Thesis Supervisor Professor Timothy M. Swager: , -L i \ O 2 The Development and Application of Metal-Catalyzed Processes for Organic Synthesis by Edward J. Hennessy Submitted to the Department of Chemistry on May 19, 2005 in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy at the Massachusetts Institute of Technology ABSTRACT Chapter 1. Copper-Catalyzed Arylation of Stabilized Carbanions A mild, general catalytic system for the synthesis of a-aryl malonates has been developed. Aryl iodides bearing a variety of functional groups can be effectively coupled to diethyl malonate in high yields using inexpensive and widely available reagents, making this a superior method to those previously described that employ copper reagents or catalysts. The functional group tolerance of the process developed makes it complementary to analogous palladium-catalyzed couplings. Importantly, a set of mild reaction conditions has been developed that minimize product decomposition, a problem that had not been addressed previously in the literature.
    [Show full text]
  • Design, Synthesis, and Supramolecular Surface Chemistry Of
    DESIGN, SYNTHESIS, AND SUPRAMOLECULAR SURFACE CHEMISTRY OF BI- AND TRIDENTATE SURFACE ANCHORS FOR NANOSCIENCE AND NANOBIOTECHNOLOGY A Dissertation Presented to The Graduate Faculty of the University of Akron In Partial Fulfillment Of the Requirements for the Degree Doctor of Philosophy Hui Wang August, 2007 DESIGN, SYNTHESIS, AND SUPRAMOLECULAR SURFACE CHEMISTRY OF BI- AND TRIDENTATE SURFACE ANCHORS FOR NANOSCIENCE AND NANOBIOTECHNOLOGY Hui Wang Dissertation Approved: Accepted: _______________________ _______________________ Advisor Department Chair Dr. Jun Hu Dr. Kim C. Calvo _______________________ _______________________ Committee Member Dean of the College Dr. Gerald F. Koser Dr. Ronald F. Levant _______________________ _______________________ Committee Member Dean of the Graduate School Dr. David A. Modarelli Dr. George R. Newkome _______________________ _______________________ Committee Member Date Dr. Claire A. Tessier _______________________ Committee Member Dr. Robert R. Mallik ii ABSTRACT This dissertation describes the design, synthesis, and supramolecular surface chemistry of bi- and tri-dentate surface anchors for nanoscience and nanobiotechnology. Molecular electronic device candidates, based on the tridentate surface anchor 2,4,9-trithia-tricyclo[3.3.1.13,7]decane, were used to bridge two ruthenium metal clusters. These well-designed ruthenium complexes were used as nanometer-sized molecular connector/metal cluster models to investigate the surface binding characteristics of tridentate surface anchor-metal junctions. Bi-dentate surface anchors, 1,4-dimercapto-2,3-dimethyl-butane- 2,3-diol and 4,5-dimethyl-2-(4-vinyl-phenyl)-[1,3,2]dioxaborolane-4,5-dithiol, were synthesized. They were used as ligands for stabilizing gold nanoparticles by two methods: direct reduction reaction, and ligand exchange reaction with triphenylphosphine-stabilized gold nanoparticles.
    [Show full text]
  • Development of Novel Peptide Nucleic Acids A
    b-Dicarbonyl compounds Compounds having two carbonyl groups separated by an intervening carbon atom are called b-dicarbonyl compounds, and these compounds are highly versatile reagents for organic synthesis. O O O O C C C R C C C OR' b b b-Dicarbonyl system b-Keto ester ** The pKa for such a proton is in the range 9-11, acidic enough to be removed easily by an alkoxide base to form an enolate. O O O H O OR C C C C C.. C + HOR H enolate anion pKa = 9-11 .. .. .. .. .. .. O . O . O O . O O C C C .. C C C R C OR' R C OR' R C OR' H H H Resonance structure of the anion of a b-keto ester Synthesis of b-keto ester (Claisen condensation) O O O NaOC H 2 2 5 CH3COC2H5 CH3CC..HCOC2H5 + C2H5OH + Na (removed by distillation) Sodiumacetoacetic ester HCl O O CH3CCH2COC2H5 Ethyl acetoacetate (acetoacetic ester) (76%) O O O O (1) NaOC2H5 R CH C + H CHC R CH2C CHCOC H + C H OH 2 OC2H5 OC2H5 + 2 5 2 5 (2) H3O R R (R may also be H) b-Keto ester Mechanism Step1 .. O O . .. + . OHC H + C H OH R CHC OC2H5 .. 2 5 RC.. H C OC2H5 2 5 H .. O . RCH C OC2H5 Step 2 .. .. .. .. O . O O O . RCH2C + . RCH2C CH C OC2H5 HC C OC2H5 . C H O . OC2H5 R 2 5 .. R .. O . O .. + . OC2H5 RCH2C CH C OC2H5 .. R Step 3 .. .. O . O H O O .
    [Show full text]
  • Lonza's Chemical Network Diketene and HCN Derivatives, Heterocycles
    Lonza’s chemical network Diketene and HCN derivatives, heterocycles and basic chemicals catalog Pharma&Biotech Nutrition Agriculture MaterialsScience PersonalCare Diketene and HCN derivatives, heterocycles and basic chemicals catalog Content About Lonza 3 Introduction 4 Diketene / ketene derivatives 6 Esters 6 Arylides 7 Alkylamides 8 Pyrazolones 9 Dehydroacetic acid 9 Lonzamon monomers 10 Other diketene derivatives 10 HCN derivatives 12 Heterocycles 14 Basic chemicals 16 Others 17 Alphabetical index 18 About Lonza Lonza is the global leader in the production and support of active phar- From 1897 to the present day combining Swiss tradition with global maceutical ingredients both chemically and biotechnologically. Biophar- experience, the company has had an enterprising character, adapting maceuticals are one of the key growth drivers of the pharmaceutical and its offerings and services to the needs of customers and to changing biotechnology industries. technologies. Throughout our history, we have maintained a strong culture of performance, results and dependability that is valued by all Lonza has strong capabilities in large and small molecules, peptides, of our customers. amino acids and niche bioproducts which play an important role in the development of novel medicines and healthcare products. In addition, Lonza’s cracker in Visp is the back bone of a comprehensive fully back- Lonza is a leader in cell-based research, endotoxin detection and cell ward integrated chemical network. Our product portfolio consists of therapy manufacturing. Furthermore, the company is a leading provider HCN- and diketene derivatives as well as basic chemicals which are key of chemical and biotech ingredients to the nutrition, hygiene, preserva- raw materials and intermediates for many sophisticated applications.
    [Show full text]
  • Acetoacetic Ester Synthesis
    Programme: B.Sc. B.ed. (Integrated) Course: ORGANIC CHEMISTRY- III Semester: VI Code: CHE-352 Topic: ETHYLACETOACETATEE Date- 07/04/2020 y Only PPe Dr. Angad Kumar Singh ForF Department of Chemistry, Central University of South Bihar, Gaya (Bihar) Note: These materials are only for classroom teaching purpose at Central University of South Bihar. All the data taken from several books, research articles including Wikipedia. Note: These materials are only for classroom teaching purpose at Central University of South Bihar. All the data taken from several books, research articles including Wikipedia. Ethylacetoacetate The Claisen Condensation between esters containing - hdhydrogens, promotdted byabase such as sodium ethoxy ide, toproduce a !- ketoester. One equiv serves as the nucleophilele (enolate)(eno and the other is OnlyO the electrophile which undergoes additiontion andae elimination. The use of stronger bases, e.g. sodium amide or sodiumsodUse hydride instead of sodium ethoxide, often increases the yield.d. al onal Ethylacetoacetate Note: These materials are only for classroom teaching purpose at Central University of South Bihar. All the data taken from several books, research articles including Wikipedia. Mechanism of the Claisen Condensation The reaction is driven to product by the final deprotonation step. Note: These materials are only for classroom teaching purpose at Central University of South Bihar. All the data taken from several books, research articles including Wikipedia. Mixed Claisen Condensation Like mixed aldol reactions, mixed Claisen condensations are useful if differences in reactivity exist betweenn they two esters as for example when one of the esters has no -hydrogenydrogOnlyO . Examples of such esters are: e Use ers excess Note: These materials are only for classroom teaching purpose at Central University of South Bihar.
    [Show full text]
  • Classification of Chemicals
    Classification of Chemicals Flame & Detonation Arrester Specifications PROTECTOSEAL ® The Protectoseal Company recommends that the National Butadiene would qualify as a Group D material. In each of Electric Code (NEC) Article 500, rankings of various chemi - these cases, the chemicals were primarly listed in a higher cals be used, whenever possible, to determine the suitability category (Group B), because of relatively high pressure read - of a detonation arrester for use with a particular chemical. ings noted in one phase of the standard test procedure con - When no NEC rating of the particular chemical is available, ducted by Underwriters Laboratories. These pressures were the International Electrotechnical Commission (IEC) classifica - of concern when categorizing the chemicals because these tion (Groups IIA, IIB and IIC) is recommended as a secondary NEC groupings are also used as standard indicators for the source of information for determining the suitability of an ar - design strength requirements of electrical boxes, apparatus, rester for its intended service. In general, the IEC Group IIA is etc. that must withstand the pressures generated by an igni - equivalent to the NEC Group D; the IEC Group IIB is equiva - tion within the container. It should be noted that, in each of lent to the NEC Group C; and the IEC Group IIC includes these cases, the test pressures recorded were significantly chemicals in the NEC Groups A and B. In the event of a dis - lower than those commonly encountered when testing a deto - crepancy between the NEC and the IEC ratings, Protectoseal nation arrester for its ability to withstand stable and over - recommends that the NEC groups be referenced.
    [Show full text]
  • Diethyl Malonate
    DIETHYL MALONATE PRODUCT IDENTIFICATION CAS NO. 105-53-3 EINECS NO. 203-305-9 FORMULA CH 2(COOC 2H5)2 MOL WT. 160.17 H.S. CODE TOXICITY SYNONYMS Ethyl methane dicarboxylate; Ethyl propanedioate; Diethylmalonat (German); Malonato de dietilo (Spanish); Malonate de diéthyle (French); Ethyl malonate; Malonic; Propanedioic acid diethyl ester; DERIVATION CLASSIFICATION PHYSICAL AND CHEMICAL PROPERTIES PHYSICAL STATE clear liquid MELTING POINT -50 C BOILING POINT 199 C SPECIFIC GRAVITY 1.055 SOLUBILITY IN WATER Slightly soluble pH VAPOR DENSITY 5.5 AUTOIGNITION NFPA RATINGS Health: 0; Flammability: 1; Reactivity: 0 REFRACTIVE INDEX 1.4135 FLASH POINT 93 C STABILITY Stable under ordinary conditions GENERAL DESCRIPTION & APPLICATIONS Malonic acid (also called Propanedioic Acid ) is a white crystalline C-3 dicarboxylic acid; melting at 135 -136 C; readily soluble in water, alcohol and ether; solution in water is medium-strong acidic. It can be derived by oxidizing malic acid or by the hydrolysis of cyanacetic acid. Malonic acid itself is rather unstable and has few applications. It's diethyl ester (diethyl malonate) is more important commercially. Diethyl malonate, a colourless, fragrant liquid boiling at 199 C, is prepared by the reaction of monochloroacetatic acid with methanol, carbon monoxide or by the reaction cyanoacetic acid (the half nitriled-malonic acid) with ethyl alcohol. Malonic acid and its esters contain active methylene groups which have relatively acidic alpha-protons due to H atoms adjacent to two carbonyl groups. The reactivity of its methylene group provide the sequence of reactions of alkylation, hydrolysis of the esters and decarboxylation resulting in substituted ketones. The methylene groups in 1,3-dicarboxylic acid utilize the synthesis of barbiturates; a hydrogen atom is removed by sodium ethoxide, and the derivative reacts with an alkyl halide to form a diethyl alkylmalonate.
    [Show full text]
  • Ethyl Acetoacetate (Acetoacetic Ester) (B) Diethyl Molonote (Molonic Ester) the Structure of (A) and (B) Are As
    PRESENTATION OF ENOLATES Dr. Susmita Bajpai Department of Chemistry B.N.D. College, Kanpur ENOLATES The class of compounds which contain a methylene group (–CH2–) directly bonded to the electron withdrawing groups such as –COCH3, –COOC2H5, –CN, are called active methylene compounds. This is so because the –CH2 group in them is acidic and reactive. The two examples are (a) Ethyl acetoacetate (Acetoacetic ester) (b) Diethyl molonote (Molonic ester) The structure of (a) and (b) are as This reaction is known as claisen condensation Ethyl acetoacetate (CH3COOCH2COOC2H5) • It's IUPAC name is ethyl 3-oxobutanoate • Preparation: Ethyl acetoacetate is prepared by heating ethyl acetate with sodium ethoxide in ethanol, followed by acidification. Claisen condensation • It is a condensation reaction in which, two ester molecules condensed to form an alcohol and a b-Keto ester. Therefore ethyl acetoacetate is a b-Keto ester. • Mechanism: The mechanism involves three steps: + • Step-I :- First sodium ethoxide (C2H5O–Na ) breaks into ethoxide ion and sodium ion. This ethoxide ion attacks ethyl acetoacetate to give ethyl alcohol and ester anion. Step -II: Ester anion attacks the carbonyl group of a second molecules of ethyl acetate. • Step-III: Ethoxide ion is eliminated Properties • It is a colourless pleasant smelling liquid • b.p. - 180.4oC • It is sparingly soluble in water but freely so in organic solvent. • It is neutral to litmus. Chemical properties • It is a tautomeric mixture of Keto and enol forms. Therefore it gives the reaction of the various functional groups present in the two forms. Acidity of methylene hydrogen (Formation of salt) • In ethyl acetoacetate methylene group (–CH2–) flank by two carbonyl group.
    [Show full text]
  • Recent Synthetic Applications of the Dealkoxycarbonylation Reaction
    Special Issue Reviews and Accounts ARKIVOC 2007 (ii) 1-53 Recent synthetic applications of the dealkoxycarbonylation reaction. Part 1. Dealkoxycarbonylations of malonate esters A. Paul Krapcho Department of Chemistry, University of Vermont, Burlington, VT 05405 USA E-mail: [email protected] Abstract The purpose of this review is to update (publications from 1981 to mid 2006) the synthetic applications of dealkoxycarbonylations of malonate esters, β-keto esters (and related esters with α-substituted electron-withdrawing functionalities) induced by heating with water or with water in the presence of salts (such as NaCN, NaCl or LiCl) in dipolar aprotic solvents. The presentation will be divided in two parts. In Part 1, discussion will focus on the dealkoxycarbonylations of malonate esters. Part 2 (to follow as a separate paper) will deal with the dealkoxycarbonylations of β-keto esters and α-cyano esters (and related analogues). Keywords: Dealkoxycarbonylations, Krapcho, decarbalkoxylations, malonate esters Contents 1. Introduction 2. Mechanistic Considerations 3. Esters 3.1. From monosubstituted malonate esters 3.1.1. Water alone 3.1.2. Water-salts 3.1.2.1. From alkyl, alkenyl, alkynyl and allenic malonate esters 3.1.2.2. From 2-cycloalkyl and 2-cycloalkenyl malonate esters 3.1.2.3. From aryl substituted malonate esters 3.1.2.4. From 2-heterocyclic substituted malonate esters 4. Diesters 4.1. From substrates with two malonate ester functionalities 5. Demethoxycarbonylation-Rearrangement 6. Aryl Methyl Substituted Benzenes 6.1. From bis-dealkoxycarbonylations ISSN 1424-6376 Page 1 ©ARKAT USA, Inc. Special Issue Reviews and Accounts ARKIVOC 2007 (ii) 1-53 7.
    [Show full text]
  • Enantioselective Michael Addition of Diethyl Malonate on Substituted
    ry: C ist urr m en e t Chopade, Organic Chem Curr Res 2017, 6:1 h R C e c s i e n DOI: 10.4172/2161-0401.1000178 a a r Organic Chemistry c g r h O ISSN: 2161-0401 Current Research ResearchResearch Article Article Open Accesss Enantioselective Michael Addition of Diethyl Malonate on Substituted Chalcone Catalysed by Nickel-Sparteine Complex Manojkumar U Chopade* Center for Advance Studies, Department of Chemistry, Savitribai Phule University of Pune, Pune, Maharashtra, India Abstract A series of transition metal with Sparteine a novel chiral catalyst was facilely synthesized, all of which contain a chiral Sparteine unit as a bidentate ligand. These bidentate chiral auxiliaries were found to be an efficient chiral catalyst in nickel-mediated, enantioselective Michael addition of Diethyl malonate to substituted chalcone. The corresponding adducts were obtained in good yields (80-91%) under simple and clean reaction condition. of asymmetric catalysis [19]. Nitrogen-containing chiral ligands have Keywords: NiCl2; Sparteine; Chalcones; Diethyl malonate; Michael addition distinct advantages, including easy to synthesis, highly stable and more importantly, nitrogen atom that can stabilize the central metal Introduction at a high valence [20,21]. Reasoning that, nitrogen-containing ligands Enantiopure bidentate ligands of transition metal complexes with, are frequently used in asymmetric synthesis [22,23]. There are several oxygen, phosphorus and nitrogen donor sites have been the subjected practical benefits nitrogen-containing chiral ligands such as simple to considerable attention and their active potential as chiral catalyst in reaction operation, mild reaction condition and environmentally being asymmetric synthesis was discovered [1-4].
    [Show full text]