Chemistry Commons^™

The Synthesis Of Analogs Of Toxoflavin And Fervenulin As Potential Antimetabolites, Bernadette Kuo Billings

Theses and Dissertations

The synthesis of analogs of toxoflavin: 1,3,4,6-tetramethyl-1,5,6, 7-tetrahydropyrimido[4,5-c]-5,7-pyridazinedione; 1,6-dimethyl-3,4-diphenyl-1,5,6,7-tetrahydropyrimido[4,5-c]-5,7-pyridazinedione; 3,5,7-trimethyl-8-phenyl-2,3,4,8-tetrahydropyrido[2,3-d]-2,4-pyrimidinedione are discussed. The synthesis of analogs of fervenulin: 3,4,6-trimethyl-5,6,7,8-tetrahydropyrimido[4,5-c]-5,7-pyridazinedione; 6-methyl-3,4-diphenyl-5,6,7,8-tetrahydropyrimido[4,5-c]-5,7-pyridazinedione; 2-hydroxy-3,5,7-trimethyl-4(3H)pyrido[2,3-d]-2,4-pyrimidinone are discussed. Several intermediates have been prepared: 6 -methylamino-3-methyluracil by a new method; 6-n-propylamino-3-methyluracil: 6-n-butylamino-3-methyluracil and 3-ethyl-2-ethylthio-2-hydroxy-4(3H)pyrimidinone.

Hard And Soft Nucleophilic Substitution Patterns In Amino-Methylsulfonylazines, Calvin Wilson Mccausland

Theses and Dissertations

The selectivity observed with 2,4,7-triamino-6-methylsulfonyl-pteridine when reacted with "hard" aliphatic amines and "soft" aryl-thiols resulting in amine exchange at the 2-, 4-, and 7-positions and displacement of the 6-methylsulfonyl moiety, respectively, was further investigated in other ring systems. The substrates tested were disubstituted with amino- and methylsulfonyl- moieties, and included the benzene, pyridine, pyrazine, quinoxaline, quinazoline and pteridine ring systems. The methylsulfonyl moiety is preferentially displaced by both thiols and amines with quinoxaline and quinazoline substrates, and is more reactive towards displacement by thiol than amine nucleophiles. Amine exchange occurs with the quinoxaline substrate subsequent to displacement of the methylsulfonyl …

Synthesis Of Tcne And Tcnq Derivatives And The Preparation Of Conducting Polymers, Michael L. Runge

Theses and Dissertations

Tetracyanoethylene and tetracyanoquinodimethane were reacted with various N,N-dimethyl-a, w-alkyldiamines to produce TCNE and TCNQ diamino and monoamino derivatives. NMR and ir spectra of the monoamino derivatives, 1-(N,N-dimethyl-a,w-alkyldiamino)-1,2,2-tricyanoethylenes and 7-(N,N-dimethyl-a,w-alkyldiamino)-7,8,8-tricyanoquinodimethans, indicated that these compounds exhibited strong nitrogen-hydrogen-nitrogen intramolecular hydrogen bonding. This phenomenon was corroborated by molecular weight and preliminary x-ray analyses.

The 1,1-bis(N,N-dimethyl-a,w-alkyldiamino)-2,2-dicyanoethylene and 7,7-bis(N,N-dimethyl-a,m-alkyldiamino)-8,8-dicyanoquinodimethan derivatives were polymerized with a,m-alkyldibromides containing two to six methylene groups to produce the corresponding ionene polymers. Viscosity measurements of the polymers indicated that the TCNE copolymers were generally of higher molecular weight than the corresponding TCNQ copolymers.

The two polymer series were treated with lithium …

Calorimetric Determination Of The Interaction Of Cu, Fe, And V Oxides With So₂ And Measurement Of Sulfur (Iv) And Sulfur (Vi) In Particulate Samples From Utah Valley, Douglas F. Cannon

Theses and Dissertations

The adsorption of SO2 by metal oxides suspended in decane were studied by calorimetric titration. The adsorption per surface area decreases in order CuO > Cu2O > Fe2O3 > V2O5. An Andersen High Volume sampler was used to obtain particulate samples from five sites in Utah County. Particulate sulfur (IV) and sulfur (VI) was analyzed by thermometric titration with K2Cr2O7 and by a direct injection enthalpimetric determination using BaCl2. Results show that little oxidation of the S(IV) occurs after it is released from the Kennecott smelter stack.

The Effect Of Nitroalkanes On The Electrolytic Oxidation Of Tertiary Butyl Amine And Tertiary Amyl Amine, Karl Lloyd Bergen

Theses and Dissertations

The electrolyses of tert.-butyl and tert.-amyl amines were run with a voltage of approximately 3v., as measured across the cell, with and without the presence of 1-2% nitro-tert.-alkane. A graphite anode was used; the supporting electrolyte was NaClO4; the solvent was the reacting amine(s) with 10-20% water to solubilize the NaClO4. The products were azo compounds, azoxy compounds, 1,3-disubstituted ureas and traces of nitroso compounds. In the case of tert.-butyl amine di-tert.-butyl carbodiimide was also shown to be a product. The presence of nitro compounds increased the yields of azoxy and nitroso compounds and decreased the yields of azo compounds. …

Synthesis And Stereochemistry Of 2,6,10-Triazatricyclo [5.2.1.0⁴ ¹⁰] Decane Derivatives, Susan Elaine Foulger

Theses and Dissertations

The synthesis and stereochemical aspects of derivatives of the new ring system 2,6,10-triazatricyclo [5.2.1.04,10] decane are discussed. Sythesis of 2-nitro-2-methyl-1,3-disubstitutedaminopropanes, followed by reduction of these compounds to 2-amino-2-methyl-1,3-disubstituted aminopropanes afforded the necessary starting materials for a cyclization reaction similar to that resulting in already known 2,6-dioxa-10-azatricyclo [5.2.1.04,10] decanes. Reaction of the triamines with 2,5-hexanedione resulted in 2,6-disubstituted-1,4,7-trimethyl-2,6,10-triazatricyclo [5.2.1.04,10] decanes. The stereochemical aspects of this ring system are interesting from the standpoint of nitrogen inversion barriers on nitrogens 2 and 6. Existence of a high inversion barrier for these nitrogens in shown by isolation of different diastereomers of the tricycle. Methods …

Macrocyclic Polyether Sulfide Syntheses :|Bthe Preparation Of Thia-Crown-6, 7, And 8 Compounds, Robert Askew Reeder

Theses and Dissertations

Macrocyclic polyether sulfides have been prepared by reacting an oligoethylene glycol dichloride with a dithiol in refluxing basic ethanol. The following new compounds were prepared: 1,5-dithia-(19- crown-6), 3-hydroxy-1,5-dithia-(19-crown-6), 1,4-dithia-(21-crown-7), 3-hydroxy-1,5-dithia-(22-crown-7), and 1,4-dithia-(24-crown-8). One other previously reported macrocyclic polyether sulfide was also prepared. The thesis includes a review of macrocyclic sulfides and other related compounds, the thermodynamics of interaction of several macrocyclic polyether sulfides with Ag^+, Hg^2+, and Pb^2+ ions, and a discussion of the structure of these materials.

A Comparative Investigation Of Mammalian Serine Transhydroxymethylases, Sanha Panichajakul

Theses and Dissertations

Serine transhydroxymethylase was purified one thousand-fold from bovine brain and one hundred and twenty-fold from bovine liver. Both enzymes were yellow due to the presence of the coenzyme pyridoxal 5'-phosphate. Polyacrylamide gel electrophoresis of the liver enzyme showed one major band containing 95% of the protein, while in the case of the brain enzyme two major bands of nearly equal intensity were observable. The specific activity of the crude liver enzyme was about sixty times higher than that of brain. The liver enzyme was also more heat stable than the brain enzyme. The purified enzymes exhibited L-allothreonine and L-threonine aldolase …

The Kinetics And Mechanism Of A Free Radical Decay In Aqueous Solution, Denzel Lee Fillmore

Theses and Dissertations

The decomposition of nitrosyl disulfonate ion was studied in strongly alkaline solution of 10-2 to 5 m sodium hydroxide. The decomposition was found to be first-order in both hydroxide and nitrosyl disulfonate ions. A multi-step mechanism involving sulfite ion, sulfite ion radical and nitrosyl monosulfonate ion radical as intermediates was proposed, with the initiating step being the SN2 replacement of a sulfite ion by a hydroxide ion. The rate constant for the initiating step ranged from 1.2 x 10-7 to 2.25 x 10-5 M-1s-1 for the solution concentration range of the study. The products of the decomposition were identified as …

Composition, Time, And Size Distributions Of Airborne Particulate Material In Utah Valley, Douglas R. Lawson

Theses and Dissertations

The Lundgren impactor is used to determine the variations in time and size distributions of particulate matter in Utah Valley. Charged particle X-ray fluorescence is employed in this study to determine elemental concentrations. Air samples are taken during two 24-hour periods in downtown Provo, 24 hours near U.S. Steel Corporation, Geneva Works, and 12 hours at Lindon Elementary School, and diurnal particulate variations are compared. The amounts of lead and bromine are four times greater on a weekday than on a Sunday in downtown Provo, suggesting the effect of the automobile on atmospheric particulate concentrations. Paraffin coated impaction surfaces are …

Development Of Proton-Induced X-Ray Emission Techniques With Application To Multielement Analyses Of Human Autopsy Tissues And Obsidian Artifacts, Kirk Kay Nielson

Theses and Dissertations

A method of trace element analysis using proton-induced X-ray emission (PIXE) techniques with energy dispersive X-ray detection methods is described. Data were processed using the computer program ANALEX. PIXE analysis methods were applied to the analysis of liver, spleen, aorta, kidney medulla, kidney cortex, abdominal fat, pancreas and hair from autopsies of Pima Indians. Tissues were freeze dried and low temperature ashed before analysis. Concentrations were tabulated for K, Ca, Ti, Mn, Fe, Co, Ni, Cu, Zn, Pb, Se, Br, Rb, Sr, Cd and Cs and examined for significant differences related to diabetes. Concentrations of Ca and Sr in aorta, …

The Purification And Characterization Of Methylmalonyl Coa Mutase From Bovine Brain, Damon Martin

Theses and Dissertations

Methylmalonyl CoA mutase has been purified over 2300-fold from bovine brain using fractional precipitation, ion exchange resins, and gel filtration procedures. The crude extract had an equal mixture of mutase in the halo- and apoenzyme form. After the final purification step the ratio had changed to 86% holo-enzyme and 14% apoenzyme. The mutase enzyme had a pH optimum of 7. 0 in Tris-HCI buffer. The Km values for L-methylmalonyl CoA and succinyl CoA were 7.7 x 10^-4 M and 1.8 x 10^-4 M respectively. The equiIibrium constant in the direction of succinyl CoA formation was 19. Inhibition with N-ethylmalei-mide was …

Part I. Catalytic Hydrocarbon Reforming By Technetium Catalysts.|Npart Ii.|Pacetone Azine And 3,5,5-Trimethyl-2-Pyrazoline Adducts Of Palladium Chloride, James Lynn Palmer

Theses and Dissertations

Technetium catalyzes hydrocarbon reforming reactions of dehydrocyclization, isomerization, hydrogenolysis, and coke formation. A kinetic equation was derived and E_a and A_o evaluated for dehydrocyclization of n-heptane, isomerization of n-pentane, and dehydrogenation of methylcyclohexane and cyclohexane. The results were related to the metal, the form of the catalyst, catalyst support, and the deactivation of the catalyst. The effect of sulfur compounds was determined. No residual radioactivity in the product was observed. The ligands, acetone azine (AA) and 3,5,5-trimethyl-2- pyrazoline (Py), reacted with (C_6H_5CN)_2PdCl_2 to form adducts, L_2PdCl_2 and (LPdCl_2)_n. Their structures were characterized by spectroscopic methods and some molecular weights determined. …

The Attack Of Hard And Soft Nucleophiles On 6-Methylsulfonyl-, 6-Methylsulfinyl-, And 6-Methylthioaminopteridines, William David Johnston

Theses and Dissertations

In an attempt to prepare 6-anilino and 6-benzylaminopteridines, 2,4,7-triamino-6-methylsulfonyl and 2,4,7-triamino-6-methylsulfinylpteridines were prepared and reacted with a number of benzylamines and aniline. These hard nucleophiles gave amine exchange products with no displacement at the 6 position. Aliphatic amines gave exchange in the 2,4-and 7-positions. The exchange occurring in the 7-position must be occurring by an AE mechanism. This is the first such exchange reported in a ring other than a 1,3-azine. Aniline gave no exchange product except in an acid catalyzed reaction, and then gave exchange in only the 2 and 4-positions. Numerous reactions on related substrates, are reported. Soft …

A Remote Aerosol Sampler To Be Used With Charged-Particle X-Ray Fluorescence Analysis, Steven Dee Rowley

Theses and Dissertations

A remote aerosol sampler, capable of up to 3 weeks continuous sampling has been developed. It consists of an Anderson 2000 Inc. mini-sampler or personnel monitor requiring an air flow of 1.4 e/min, a flow meter, a vacuum meter, a bleed valve, a dry gas volume meter, and a pump. The pump is a Brailsford Model TD-4X2, and operates on a 24 volt D.C. power supply. The sampler consists of four impaction stages with a 0.4 μ Nuclepore backup filter. Particulates are removed from the plates in an ultrasonic cleaner with hexane solvent. The suspended particulates are collected on a …

Thermodynamic Stability Constants Of Silver Bromide Complexes In Water And Water-Acetone Mixtures Determined By Ion-Selective Electrode Measurements, Arthur Lee Cummings

Theses and Dissertations

Thermodynamic equilibrium constants for silver(I) bromide complexes were determined by ion-selective membrane electrode potential measurements in water and in mixtures of water and acetone of approximately 5, 10 and 15 percent acetone by weight. Values of the solubility product constant were determined in each solvent system by calibration of a silver bromide membrane electrode with silver nitrate solutions and with sodium bromide solutions. Stability constants of silver(I) bromide complexes were determined using a silver ion-selective, silver sulfide membrane electrode in unsaturated solutions in which the formal concentrations of silver(I) and of bromide ranged from approximately I x 10-8 to 7 …

Trace Metal Analysis Of Hair By Charged Particle X-Ray Fluorescence, George M. Allison

Theses and Dissertations

A method for the trace element analysis of hair by charged particle X-ray fluorescence is presented. The validity of the method is shown by the analysis of NBS SRM 1577--Bovine Liver, obtained from the National Bureau of Standards. Excellent correlation is obtained between results from the analysis by the X-ray method and those certified by NBS. Hair samples are ashed by a low temperature oxidation process and analyzed by the X-ray method. The results from the analysis by the X-ray method are compared to those obtained from the analysis of the same hair samples by atomic absorption. Good correlation is …

Macrocyclic Polyether Sulfide Syntheses, The Preparation Of Thia-Crown-3, 4, 6, And 7 Compounds, Yau-Kwong Joseph Hui

Theses and Dissertations

Macrocyclic polyether sulfides have been prepared by reacting an oligoethylene glycol dichloride with a dithiol or sodium sulfide in ethanol. The following new compounds were prepared: 1-thia-(9-crown-3), 1,4-dithia-(9-crown-3), 1,4-dithia-(12-crown-4), 1,4,7-trithia-(12-crown-4), 1-thia-(18-crown-6), I,4-dithia-(18-crown-6), 1,7-dithia-(18-crown-6), 1,4,7-trithia-(18-crown-6), 1,7-dithia-(21-crown-7), 1,4,7-trithia-(21-crown-7). Four other previously reported macrocyclic polyether sulfides were also prepared. The symmetry of the nmr spectra of these compounds give added evidence for the proposed ring structures. The following subjects were presented and discussed: studies of cyclization by-products, dependence of cyclization yield on the size of the rings, high dilution principle and its application, medium-sized rings, effect of hetero-atoms on cyclization and melting point …

The Solution Photochemistry Of Benzaldehyde In Benzene, Ethanol, And 1-Hexyne, Ronald Douglas Knudsen

Theses and Dissertations

The photoreactions of benzaldehyde in benzene, ethanol, and 1-hexyne have been studied. Irradiation of benzaldehyde in benzene produces benzoin (I), hydrobenzoin (II), and deoxybenzoin (III). Irradiation of benzoin (I) in this solvent results in benzaldehyde formation as well as small amounts of (II) and (III). The ethanol irradiation of benzaldehyde resulted, predominantly, in the formation of (II) with (I) formed in small amounts. The photolysis of benzaldehyde in 1-hexyne produces (I), (II), (III) cis-2-heptenophenone (VII), trans-2-heptenophenone (VIII), heptanophenone (IX), and 2-(n-butyl)- 1,4-diphenyl-1,4-butanedione (X). Mechanistic pathways for the formation of these photoproducts are discussed. Separation and characterization of cis- and trans-2- …

A Calorimetric Study Of Metal Binding In Carboxypeptidase, Carbonic Anhydrase And Concanavalin A, Gary E. Hatch

Theses and Dissertations

The purpose of this study was to perfect a new calorimetric method for identifying and counting ionizable chemical groups on proteins. To do this, calorimetric and electrometric titrations were performed (using HCl and NaOH as titrant) on native carboxypeptidase, carbonic anhydrase and concanavalin A plus their apo and organic ligand bound derivatives. Readily identifiable endpoints were seen in the calorimetric titrations and general agreement was found between ΔH values obtained in this study and literature ΔH values of model compounds undergoing the same reaction. Imidazole groups were those most easily counted. Many assumptions had to be made, however, in concluding …

State Of Bacterial Dna After Uptake Into The Roots Of Germinating Barley Seeds, Larry Dale Lawson

Theses and Dissertations

Germinating barley seeds have been shown to take up Bacillus subtilis DNA labelled with 5-bromouracil and tritiated thymidine and retain the DNA in the root system without substantially degrading it. The percentage of bacterial DNA recovered from the total root DNA was independent of the amount of bacterial DNA available for uptake. Four observations indicated the stability of bacterial DNA after uptake into barley roots: (1) the bacterial DNA retained its transforming ability after recovery from the roots; (2) the labelled B. subtilis DNA showed similar CsCl density gradient patterns before uptake and after uptake; (3) most of the radioactivity …

I. An Isothermal Titration Microcalorimeter. Ii. Importance Of Micronutrients In Nutrition. Iii. Zinc Bibliography, John Willard Gardner

Theses and Dissertations

I. An isothermal titration microcalorimeter having a colume of 4 ml and capable of temerature control to ±2 x 10-5°C is described. Major components include a constant temperature water bath controlled to ±3 x 10-4°C, a platinum reation vessel, and an isothermal control circuit consisting of constant Peltier thermoelectric cooling and variable Joule heating controlled by a thermistor in an AC Wheatstone bridge circuit. The calorimeter was tested by measuring the heat of ionization of water and was found to produce data accurate to ± 0.1% where small samples are used such as in the investigation of many biological systems.

Development Of Standard Procedures For Determination Of [Delta]G° (K), [Delta]H° And [Delta]S° Values Via Potentiometric And Calorimetric Titration Techniques, Jack Hugh Ruckman

Theses and Dissertations

Standard computer techniques were developed for computation of ΔG° values from potentiometric titration data and ΔH° values from calorimetric titration data. The procedures developed can be used for any systems having the general equations HA = W^+ + A^- ; H_2A = 2H^+ + A^2- ; and H_3A = 3H^+ + A^3-, where the proton ionizations may be consecutive or simultaneous. The thermodynamic values ΔG°(K), ΔH° and ΔS° were determined for the ionization of protons from the protonated compounds methionine (-NH_3^+ group only), phosphoethanalomine and phosphoserine. The compounds studied were selected because they contain one, two and three ionizable protons …

The Purification And Characterization Of Cytochrome B₅ From Porcine Kidney, M. Dean Klingler

Theses and Dissertations

A soluble form of cytochrome b_5, with a 413/280 nm ratio of nearly unity, has been isolated and purified from porcine kidney using fractional precipitation, ion exchange resins, and gel filtration procedures. The cytochrome b_5 shows heat stability up to 50° and is stable in the pH range 6.0 to 8.5. The oxidized protein exhibits an absorption maximum at 413 nm, while the reduced form shows three peaks: 423, 526, 556 nm. Molecular weight determinations have given variable results, suggesting the possibility of a polymer composed of four and eight units of a 13,500 molecular weight protomer. This study has …

|Ni.|Pa Calorimetric Study Of The Heat Of Ionization Of Water At 10 And 40°C, And,|Nii.|Pa Calorimetric Determination Of The Heat Of Reaction Of Tris (Hydroxymethyl) Aminomethane (Tham) With Hydrochloric Acid In Aqueous Solution At 10, 25, And 40°C, Griffith Lyn Kimball

Theses and Dissertations

The heat of neutralization, ΔH_-N, of perchloric acid with sodium hydroxide has been determined at 10 and 40° in a low ionic strength, μ, region using a nonisothermal, constant-temperature-environment solution calorimeter. Correction of the data to infinite dilution by extrapolation of a plot of ΔH_-N vs μ^0.5 gives values at zero ionic strength for the heat of ionization of water of 14.216 and 12.695 kcal/mole, respectively, at 10 and 40° . The data are correlated with those of earlier workers to give an equation allowing the calculation of the heat of ionization of water at zero ionic strength over the …

⁷Li(D,P)⁸Li Excitation Function :|Be[Subscript D] = 0.623 Mev To 1.968 Mev, Albert E. Schilling

Theses and Dissertations

In this study the excitation function for the ^7Li(d,p)^8Li reaction is determined at incident deuteron energies ranging from 0.623MeV to 1.968MeV by counting the delayed alpha-particles as a result of the ^8Li beta decay. This excitation function reveals resonances at 0.777±0.012MeV and 1.031±0.015MeV with cross sections of 202±9mb and 188±8mb respectively. The uncertainty in the cross section values was due to three independent sources of error within this experiment, the solid angle, the ^8Li half-life, and the target (LiF) thickness. The uncertainty in the energy values was determined from an energy calibration of the accelerator used in this study. Resonances …

Reactions Of N₂F₄ And Sf₆ With H₂ Induced By Co₂ Laser Pulses And By Electrical Discharge, John Leslie Lyman

Theses and Dissertations

A high power pulsed CO_2 laser was used to induce reactions in gas mixtures containing either N_2F_4 or SF_6. The rate of laser induced dissociation of N_2F_4 to NF_2 was as much as 1000 times faster than the thermal rate, and the rate law was of lower order than the thermal, bimolecular rate law. Explosion threshold and induction time data were obtained for butene stabilized mixtures of N_2F_4 and H_2. HF laser gain was observed during the first few microseconds of CO_2 laser pulse, but it was strongly quenched by the explosion. The laser driven reaction of SF_6 with H_2 …

Thermodynamic Equilibrium Formation Constants And Molal Concentrations Of The Complexed Mercury-Containing Species Of Mercuric Chloride In Added Hydrochloric Acid And Methanol-Water Solvent Mixtures, Karl Jennings Walker

Theses and Dissertations

Saturated solutions of mercuric chloride in different methanol-water and hydrochloric acid solvent mixtures were equilibrated at 25.00 ± 0.01°C. Total mercury and free chloride concentrations were determined by analytical procedures and the data were analyzed with the aid of the computer. Tabulated below are the results of this study: [--see thesis for table--]

The Determination Of Thiamin And Its Derivatives In Brain Tissue Of Control, Thiamin-Deficient, Oxythiamin- And Pyrithiamin-Treated Rats, David S. Murdock

Theses and Dissertations

The determination of total thiamin, free thiamin, thiamin di phosphate (TDP) plus thiamin triphosphate (TTP), and total α- hydroxyethylthiamin (HET) levels in rat brain in control, deficient, oxythiamin- (OTH) and pyrithiamin- (PTH) treated rats was accomplished. It was found that the TDP + TTP/thiamin ratio observed in the thiamin-deficient, OTH- and PTH-treated rats was constant and did not differ from the ratio observed in the control rat brains. The brain levels of TDP + TTP decreased to 39% and 12% of the control thiamin levels in deficient and PTH-treated rats respectively. The brain HET and TDP + TTP levels of …

Electrolytic Synthesis Of [Gamma]-Diketones, Leon F. Pahler

Theses and Dissertations

Four γ-diketones were synthesized by using a modification of the Kolbe electrolytic condensation of β-ketocarboxylic acids. [--see equation in thesis--] The following γ-diketones were synthesized in moderate yields: 2,5-hexanedione, 4,7-decanedione, 2,2,7,7-tetramethyl- 3,6-octanedione, and 1,4-diphenyl-1,4-butanedione (34, 39, 23, and 27, respectively). However, attempted preparation of the following γ-diketones failed: 3,4-dimethyl- 2,5-hexanedione, 3,3,4,4-tetramethyl-2,5-hexanedione, and 1,4-di(2-thienyl)-1,4-butanedione. Attempts to electrolytically condense α-alkyl and α, α-dialkyl substituted monocarboxylic acids have been reported and all attempts have ended in failure; similarly, the attempts to synthesize 3,4-dimethyl and 3,3,4,4-tetramethyl- 2,5-hexanedione from 2-methyl and 2,2-dimethyl-3- oxobutanoic acid, respectively, failed. The preparation of 1,4-di(2-thienyl)-l,4-butanedione failed because the product or …