bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies of Inorganic Ion Exchangers. III. Ion Exchange Properties of Ti(HPO4)2·0–1/2H2O to Alkali Metal and Ammonium Ions
Authors: Kobayashi Etsuro 
Published: July 2006

Abstract
In order to develop an inorganic ion exchanger for industrial use, the ion exchange behaviour of Ti(HPO4)2·0–1/2H2O with alkali metal and ammonium ions has been investigated. The ion exchange capacities of Ti(HPO4)2·1/2H2O (hemihydrate) have been determined by forward and backward titration. The saturation ion exchange capacities (QA) of the hemihydrate to Li, Na, K, Cs, and NH4 (M) ions by the forward titration method were 1.9, 3.2, 4.1, 2.5, and 3.7 meq/g at pH 4.5, respectively. The ion exchange capacities (Q°) of the hemihydrate from 0.1 M MCl were 0.31, 1.84, 2.31, 0.21, and 1.01 meq/g to each of the ions. The selectivity quotients (KHM) estimated from the QA and Q° were 0.028, 3.77, 15.7 0.008, and 0.255 to each of the ions, and the selectivities of the hemihydrate increased in the order Cs+&lt;Li+&lt;NH4+&lt;Na+&lt;K+. The empirical formula of the 50% ion exchange products derived from the hemihydrate may be represented by TiMH(PO4)2·0–1/2H2O, (where, M=Na, K, and NH4). The ion exchange of Li and Cs ions did not take place completely however to give a 50% ion exchanger, and the hemihydrate was then converted into a non-stoichiometric compound.
Kinetic Studies of the Electron Transfer Reaction in Iron(II) and Iron(III) Systems. VIII. The Effect of Hexamethylphosphoric Triamide on the Electron Transfer Reaction in Aqueous Solution
Authors: Wada Goro , Nakago Sayuri , Abe Yuriko 
Published: July 2006

Abstract
The kinetics and mechanism of the electron transfer reaction between Fe(II) and Fe(III) in mixed solvents of water and hexamethylphosphoric triamide (HMPA) were studied. The apparent rate constant k varies depending upon [HMPA] and [H+]; k exhibits a minimum value at [HMPA]=1.5 M at constant [H+] and increases linearly with respect to [H+]−1 at constant [HMPA]. Judging from the basicity constant of HMPA, the complex formation constant of Fe(hmpa)3+, and the absorption spectra of aqueous solutions containing Fe(II), Fe(III), HMPA, and HClO4, the existing species in the reaction systems are mostly Fe2+aq, Fe3+aq, Fe(OH)2+, Fe(hmpa)3+, and Fe(hmpa)(OH)2+ at low concentrations of HMPA. Therefore, the probable reaction paths are Fe2+–Fe3+, (k0); Fe2+–Fe(OH)2+, (kH); Fe2+–Fe(hmpa)3+, (kL); and Fe2+–Fe(hmpa)(OH)2+, (kHL) at the concentration range of [HMPA]=0–1 M and [HClO4]=0.03–0.2 M. The occurrence of a minimum value of kvs. [HMPA] is reasonably understood by taking the complex formation between Fe(III) and HMPA into account in reaction rate equation. If the hydrolysis constants of both Fe(OH)2+ and Fe(hmpa)(OH)2+ are considered to be nearly of the same order, the value of kH are approximately ten times larger than that of kHL. At higher concentrations of HMPA, the higher Fe(III)-complexes with HMPA might take part in the electron transfer reaction.
Synthetic Inorganic Ion-exchange Materials. XX. Ion-exchange Properties of Crystalline Antimonic(V) Acid with Alkaline Earth Metal Ions
Authors: Abe Mitsuo 
Published: July 2006

Abstract
A stoichiometrical ion-exchange was observed for all the systems of Mg2+, Ca2+, Sr2+, and Ba2+ with H+ in the crystalline antimonic(V) acid as a cation exchanger. The selectivity sequence, Mg2+&lt;Ba2+&lt;Sr2+&lt;Ca2+, has been found for the ion-exchange reactions in 0.1 M nitrate salt solutions of different alkaline earth metals. Breakthrough and further elution studies were carried out in order to test the reversibility of the ion-exchange reactions. X-Ray analysis indicates that a solid solution forms for the ion-exchange system of the alkaline earth metal ions in the crystalline antimonic(V) acid.
Synthesis, Absorption and CD Spectra of [Co(amino alcohol)(N)2(O)2]-type Complexes
Authors: Okazaki Kenichi , Shibata Muraji 
Published: July 2006

Abstract
Complexes of the [Co(amOH)(N)2(O)2]-type, where amOH represents 2-aminoethanol or (S)-2-amino-1-propanol and (N)2(O)2 represents (gly)2, (β-ala)2, (ox)(en) or (ox)(NH3)2, have been prepared and characterized on the basis of absorption and PMR spectra. Splitting of the T2g band has been observed in the solution spectra of certain isomers of the [Co(gly)2(eta)], [Co(gly)2(S-pra)], or [Co(β-ala)2(eta)] complex. Using the crystal spectral data of the isomers of [Co(gly)2(eta)], the σ- and π-antibonding parameters for the ligating alcoholate O atom have been estimated and it has been found that each parameter shows a higher value than the corresponding parameters for the other ligating N and O atoms. The CD spectrum, in the T2g region, of fac-[Co(gly)2(eta)] has shown an intense peak at ca. 25000 cm−1, and the vicinal effect curve of each isomer of the [Co(gly)2(S-pra)] complex has shown an intense peak at the same frequency.
Preparation and Stereochemistry of Optical Isomers of the Tris-(3,3′-dimethyl-2,2′-bipyridyl N,N′-dioxide)chromium(III) Complex
Authors: Kanno Hideaki , Kashiwabara Kazuo , Fujita Junnosuke 
Published: July 2006

Abstract
A new ligand, (R)- and (S)-3,3′-dimethyl-2,2′-bipyridyl N,N-dioxide(mbdo) forms three diastereomers(I, II, and III) of [Cr(mbdo)3]3+ by the reaction with [Cr(H2O)6]3+ in water. (I) was assigned to a pair of enantiomers, Δ(RRR) and Λ(SSS), and (II) and (III) to either a diastereomeric pair of Δ(RRS) and Λ(SSR) or Δ(SSR) and Λ(RRS). While the racemic (I) was resolved by SP-Sephadex column chromatography, (II) and (III) isomerized in water to each other (II\ightleftarrowsIII) by exposure to ultraviolet light, were resolved by the reaction of [Cr(H2O)4(R or S)-mbdo]3+ with a stoichiometric amount of (S or R)-mbdo. The circular dichroism spectra of these optically active isomers were measured in aqueous solutions and compared with those of complexes of the [CrO6]-type of known absolute configuration. The optically active free (+)589- and (−)589-mbdo were isolated by decomposing Λ(SSS)- and Λ(RRR)-[Cr(mbdo)3]3+, respectively, with edta4−. The active mbdo is optically stable even in boiling water.
Prefered Orientation and π-Bonding of the Hydroxyl Group in 1,2-Benzocycloalken-3-ols
Authors: Mori Nobuo , Kasuya Shin-ichi , Miyazaki Hitoshi , Takezawa Toshiyuki 
Published: July 2006

Abstract
The various values vOH of 1,2-benzocycloalken-3-ols observed in dilute CCl4 solutions have been explained in terms of the inclination angle of the C–O bond to the plane of the benzene ring (θ) and the conformational isomerism of the OH group with respect to the C–O bond. The vOH shift caused by OH…π bonding is angle-dependent, i.e., 9 cm−1 if θ=50–90°, or 17 cm−1 if θ=38–45°.
S
N2 Reactions in Dipolar Aprotic Solvents. VIII. Chlorine Isotopic Exchange Reaction of (Arylsulfonyl)chloromethanes, (Arylsulfinyl)chloromethanes, and 2-Chloro-1-arylethanones in Acetonitrile. A Role of the Nucleophile-substrate Interaction in the Finkelstein Reaction
Authors: Hayami Jun-ichi , Koyanagi Tohru , Kaji Aritsune 
Published: July 2006

Abstract
Chlorine isotopic exchange reactions of substituted chloromethanes [(arylsulfonyl)chloromethanes (1), (arylsulfinyl)chloromethanes (2), and 2-chloro-1-arylethanones (4)] with tetraethylammonium chloride-36Cl were studied in acetonitrile. This study enabled, for the first time, the accurate rate study of the former two classes of compounds (1 and 2) of extremely low reactivity. Both the large enthalpies of activation and the positive entropies of activation were the characteristics for these two substrates (1-p-NO2 and 2-p-NO2). High reactivity of 2-chloro-1-phenylethanone was substantiated, and was not associated with the significant secondary kinetic deuterium isotope effect. A nucleophile-substrate association that proceeds the reaction was suggested and the possible role of such an interaction was examined in the light of the intermediary of the nucleophile-substrate complex in the Finkelstein reaction.
Trans-esterification Reaction Catalyzed by Alkoxo(triphenylphosphine)copper(I) Complexes
Authors: Kubota Minoru , Yamamoto Takakazu , Yamamoto Akio 
Published: July 2006

Abstract
Alkoxocopper and phenoxocopper complexes ROCu (PPh3)n (PPh3=triphenylphosphine; n=1 for R=n-C3H7 or i-C3H7; n=2 for R=CH3, C2H5, CH2=CHCH2, C6H5CH2, or C6H5) react with esters undergoing exchange of the RO group with carboxylic esters. The alkoxocopper and phenoxocopper complexes are found to be excellent catalysts for the trans-esterification of carboxylic esters, dimethyl carbonate, and trimethyl phosphite with alcohols and phenols. A comparison of the ability of the isopropoxocopper complex as trans-esterification catalyst with that of aluminum isopropoxide and titanium isopropoxide shows the superiority of the isopropoxocopper complex. The rate of trans-esterification between p-nitrophenyl acetate and phenol follows the second-order rate law R=k[p-nitrophenyl acetate][phenol], the activation energy of the reaction being estimated to be 12.4 kcal/mol. A mechanism comprising a nucleophilic attack on the copper-bound carbonyl group of the ester by alcohol is proposed.
A Simple MO Treatment on the Nucleophilic Substitution Reactions of Six-membered Aza-aromatic Compounds
Authors: Hirota Minoru , Masuda Hideyuki , Hamada Yoshiki , Takeuchi Isao 
Published: July 2006

Abstract
Nucleophilic substitution reactions of monoaza- and diaza-naphthalenes and -phenanthrenes were discussed on the basis of an HMO calculation taking the nature of the reagent into consideration. Results were compared with the orientation of some nucleophilic substitution reactions, i.e. Chichibabin amination, phenylation by phenyllithium, and methylation by methylsulfinylmethanide ion. The nature of the reagent was explicitly taken into account as the difference in the coulomb integrals and the reagent-dependent orientation of these reactions were explained theoretically.
Reactions of Spiro[2.6]nona-4,6,8-triene Derivatives with Acids and Bases. Rearrangement to a Heptafulvene Derivative and Formation of Ether Linkage Compounds
Authors: Toda Takashi , Saito Katsuhiro , Mukai Toshio 
Published: July 2006

Abstract
Reaction of dimethyl trans-spiro[2.6]nona-4,6,8-trien-1,2-dicarboxylate with phenyllithium afforded trans-1,2-bis(hydroxydiphenylmethyl)spiro[2.6]nona-4,6,8-triene (2) in a good yield. Spirotriene 2 is very sensitive to acids and gave 8-(2,2-diphenylvinyl) heptafulvene accompanied with a quantitative amount of benzophenone by acid treatments. Although 2 is stable to basic reagents, upon treating with sodium hydride, 2 afforded 11-hydroxydiphenylmethyl-8-oxa-9-diphenyltricyclo[5.4.0.01,10]undeca-2,4-diene, and its double bond isomers. Mechanisms of the above reactions are discussed.
Optical and Magnetic Properties of Solid Cation Radical Salts Derived from Some Aromatic Hydrocarbons
Authors: Iida Yôichi 
Published: July 2006

Abstract
The optical and magnetic properties of solid cation radical salts derived from 9,10-dimethylanthracene and 9,10-dichloroanthracene were explained in terms of one-dimensional Hubbard model composed of equivalent sites of the cation radicals, while those of perylene cation radical salt, in terms of Hubbard model of cation radical dimer.
An INDO-MO Study of Peroxyacetyl Nitrate Formation
Authors: Ohkubo Katsutoshi , Sato Hiroyuki 
Published: July 2006

Abstract
The process of peroxyacetyl nitrate (PAN) formation has been disscussed on the basis of INDO calculations. The acetylperoxy radical (APR) has been found to be more reactive towards nitrogen monoxide than towards nitrogen dioxide. The bond strength of the O–O linkage in CH3C(=O)OONO, however, is weaker than that of PAN or H2O2.
Lifetime Measurement of HO2 Radical
Authors: Tsuchiya Soji , Nakamura Tomiji 
Published: July 2006

Abstract
The formation and dissipation kinetics of HO2 radical was investigated by means of UV absorption measurement in a gas mixture, H2+ca. 1% O2+a trace of Hg vapor which was irradiated by a 253.7 nm light pulse. The rate constant of the reaction 2HO2→H2O2+O2 was determined to be (2.8±0.3)×1012 cm3 mol−1 s−1.
Kinetics of the Substitution of Acetonitrile in (Acetonitrile)chlorobis(triphenylphosphine)rhodium(I) by Triphenylphosphine
Authors: Ohtani Yoshimi , Yamagishi Akihiko , Fujimoto Masatoshi 
Published: July 2006

Abstract
The substitution of coordinated acetonitrile in (acetonitrile)chlorobis(triphenylphosphine)rhodium(I) by triphenylphosphine was studied in benzene by the stopped-flow method under anaerobic conditions. The reaction was found to proceed through both an associative and a dissociative path to yield chlorotris(triphenylphosphine)rhodium(I).
Preparation and Reaction of N-Imidoyliminotriphenylphosphoranes
Authors: Yoshida Hiroshi , Ogata Tsuyoshi , Inokawa Saburo 
Published: July 2006

Abstract
N-Imidoyliminotriphenylphosphoranes 2 have been prepared by the reaction of triphenylphosphine with N-chloroamidines followed by treatment with base. 2 can react readily with hydrochloric acid or methyl iodide to give the corresponding salts. Treatment of 2 with carbon disulfide gave N-(thioacyl)iminotriphenylphosphoranes together with isothiocyanates.
The Formation of 3,4,5-Tris(substituted phenyl)-4,5-dihydro-1,2-oxazole N-Oxides in the Oxidations of (Substituted phenyl)nitromethanide Anions with Silver Nitrate or Peroxodisulfate
Authors: Fukunaga Kimitoshi , Hamanaka Kenji , Kimura Makoto 
Published: July 2006

Abstract
The reaction of an alkali metal salt of (substituted phenyl)nitromethane (1) with silver nitrate or peroxodisulfates in dimethyl sulfoxide (DMSO) gives 3,4,5-tris(substituted phenyl)-4,5-dihydro-1,2-oxazole N-oxides (2) in a good yield.
The Glow-discharge Reactions of Amines
Authors: Asada Hideki , Nomura Masakatsu , Kikkawa Sh\={o}ichi 
Published: July 2006

Abstract
The glow-discharge reactions of propylamine, dipropylamine, and N,N-dimethyl-2-methyl-1-propenylamine were studied. The results show that the primary amines yield RN=CHR′ and RNHCH2CN, and that the secondary amines produce R(R′)NCH(R″)CN. N,N-Dimethyl-2-methyl-1-propenylamine produces a series of imine and nitrile.
New Azulene Derivatives Obtained by the Sulfur Dehydrogenation of Guaiene : 3,6,9-Trimethylazuleno[4,5-b]thiophene and 2-Methylthioguaiazulene
Authors: Kohara Kazuko , Tachibana Hojun , Masuyama Yukio , Otani Yasushi 
Published: July 2006

Abstract
Two new azulene derivatives, 2-methylthioguaiazulene and 3,6,9-trimethylazuleno[4,5-b]thiophene, have been obtained and characterized, along with known 3,5,8-trimethylazuleno[6,5-b]thiophene and 2,2′-biguaiazulenyl, by the sulfur dehydrogenation of guaiene.
The Reaction of Methylferrocene with Manganese(III) Acetate
Authors: Izumi Taeko , Satou Yoshibumi , Yoshida Yoshio , Kasahara Akira 
Published: July 2006

Abstract
The oxidation of methylferrocene with manganese(III) acetate in acetic acid yielded three products which arose from the ferrocenylmethylation of methylferrocene. The reaction of methylferrocene with manganese(III) acetate in presence of styrene was also examined.
A Novel Approach to cis-Jasmone and Dihydrojasmone from 2-(2-Benzothiazolylthio)-2-(3-oxobutyl)oct-5-en(or -an)oic Acid by Electrolytic Procedure
Authors: Torii Sigeru , Tanaka Hideo , Kobayasi Yuichi , Nokami Junzo , Kawata Mikio 
Published: July 2006

Abstract
cis-Jasmone (7a) and dihydrojasmone (7b) have been synthesized by facile five-step processes starting from methyl acetoacetate involving electrolysis procedure. Methyl 2-(2-benzothiazolylthio)oct-5-en(or -an)oate, prepared from methyl 2-acetyloct-5-en(or -an)oate (1) by the reaction with the N-(2-benzothiazolylthio)morpholine, were allowed to react with methyl vinyl ketone, leading to the Michael adducts 4. After hydrolysis of 4, the corresponding acids 5 were electrolyzed to afford the desired 1,4-diketone 6 in 45–48% overall yields (based on 1), whose base-catalyzed cyclization gave 7 smoothly.
The Crystal and Molecular Structure of Perylene–2,5-Dibromo-3,6-dichloro-p-benzoquinone Complex
Authors: Kozawa Kozo , Uchida Tokiko 
Published: July 2006

Abstract
Crystals of the 1 : 1 molecular complex of perylene–2,5-dibromo-3,6-dichloro-p-benzoquinone are triclinic, with a=8.669, b=9.697, c=7.321 Å, α=103.20, β=110.92, γ=64.60°, space group P\bar1, Z=1. The structure has been determined from diffractometer data by the heavy atom method and refined using the full-matrix least-squares method to R 0.069 for 2241 independent reflections. Stacks, with alternating donor and acceptor molecules, extend along the c direction. The acceptor molecule assumes two orientations, with a population ratio 1 : 1. A small degree of correlative change in the C–C bond lengths has been found in the perylene molecule on complex formation. The geometry of the quinonoid skeleton of the acceptor is similar to those of the anils and their complexes.
An Empirical Relation between the Quenching Cross-sections of Metastable Argon and the Molecular Diameter of the Quenchers
Authors: Matsubara Kazuhiro , Oono Yoshitsugu , Kai Shoichi , Nishimura Yukio 
Published: July 2006

Abstract
For polyatomic quenchers there is a fairly accurate linear relation between σQ1⁄2 and r, where σQ is the quenching cross-section of rare gas metastables (especially Ar(3P2)) and r, the effective radius of the quencher.
Thermodynamic Study on the Adsorption of Dioctadecyl Ether at Hexane/Water Interface
Authors: Matubayasi Norihiro , Dohzono Masatake , Aratono Makoto , Motomura Kinsi , Matuura Ryohei 
Published: July 2006

Abstract
The adsorption of dioctadecyl ether was studied at hexane/water interface, as functions of temperature, pressure, and mole fraction of dioctadecyl ether in hexane. The phase transition between expanded and condensed films was observed with decreasing temperature and increasing pressure and concentration. The thermodynamic quantities associated with the adsorption such as entropy, volume, and energy change were evaluated and comparison was made with the adsorbed films of 1-octadecanol at the same interface in which phase transition takes place. It is found that the dioctadecyl ether shows small negative discontinuous changes of the thermodynamic quantities with the transition from the expanded to the condensed films.
Reactions of 4H-1-Benzothiopyran-4-ones and Related Compounds with Dimethyl Sulfate
Authors: Nakazumi Hiroyuki , Kitao Teijiro 
Published: July 2006

Abstract
4H-1-Benzothiopyran-4-ones (thiochromones) and isomeric 2H-1-benzothiopyran-2-ones (thiocoumarins) have been allowed to react with dimethyl sulfate (DMS) to study the differences in reactivity on methylation. Methylation of 2-methyl (thiochromones) with DMS afforded the blue colored dimerization products, 4-(4-methoxy-1-benzothiopyran-2-ylidenemethyl)-2-methyl-1-benzothiopyrylium perchlorates, while that of 7-methoxy-4-methyl(thiocoumarin) gave the O-methylated yellow salt, 2,7-dimethoxy-4-methyl-1-benzothiopyrylium perchlorate. Methylations of oxa analogues (coumarins) and aza analogues (2-quinolones) of thiocoumarins with DMS have also been examined. It has been found that the ease of formation of methylation products is affected by the hetero atom and carbonyl group.
Excited-state Electronic Interaction of m-Aminoacetophenone with Aliphatic Alcohols
Authors: Tanimoto Yoshifumi , Inoue Kenji , Furukawa Yoshihiko , Segawa Yoko , Itoh Michiya 
Published: July 2006

Abstract
The electronic interaction of both ground-state and excited-state m-aminoacetophenone (MAAP) with several aliphatic alcohols in nonpolar viscous solvent was investigated by steady-state and nanosecond fluorescence spectroscopies. Concentration dependence of several alcohols in liquid paraffin-hexane (LPH) mixed solvent upon fluorescence and absorption spectra suggests a complex formation of MAAP with aliphatic alcohols in the ground state. In the typical LPH solution of MAAP containing high concentration of alcohol, the complex fluorescence exhibits two-component decay and a longer wavelength fluorescence than the complex fluorescence exhibits a rise and decay. The results demonstrate that the complex in the excited state further associates with alcohol to make an exciplex including an alcohol molecule.
Wheland Polynomial. I. Graph-theoretical Analysis of the Contribution of the Excited Resonance Structures to the Ground State of Acyclic Polyenes
Authors: Ohkami Noriko , Hosoya Haruo 
Published: July 2006

Abstract
The Wheland polynomials, the set of the numbers, w(G,j), of the j-th excited resonance structures, for a number of acyclic polyenes were calculated. The relations of w(G,j) with the non-adjacent numbers, p(G,k), topological index, ZG, and the total π-electronic energy, Eπ, were analyzed in detail for linear polyenes. For branched polyenes similar results were obtained, and it was found and proved that Eπ is linearly related with the number of Dewar (singly excited)structures. Method for the numbering of atoms to generate the canonical resonance structures was discussed.
X-Ray Molecular Structure of 1-Cyano-7,8-benzo-11-oxatricyclo[4.2.2.12,5]undeca-3,7,9-triene
Authors: Kan Kojiro , Kai Yasushi , Yasuoka Noritake , Kasai Nobutami 
Published: July 2006

Abstract
C15H11ON, M.W. 221.17, monoclinic, space group P21/c, a=9.451(1), b=8.267(1), c=14.336(2) Å, β=94.37(1)°, Dm=1.31, Dc=1.32 g cm−3, Z=4, R=0.088 for 1300 non-zero reflections. The molecule has an endo-configuration, and the furan ring has an envelope form.
Properties and Structure of Alkali Aluminophosphate Glass
Authors: Kishioka Akira 
Published: July 2006

Abstract
Several series of alkali (sodium and potassium) aluminophosphate glasses were prepared with compositions of 32–63 mol % of P2O5 and the properties of these glasses were determined. In the glasses with a higher P2O5 content (P2O5\gtrsim42.5 mol % in the Na2O–Al2O3–P2O5 glass and P2O5\gtrsim45 mol % in the K2O–A12O3–P2O5 glass), the density, refractive index, and chemical resistivity increased with increasing amounts of Al2O3. In the glasses with a lower P2O5 content (P2O5\gtrsim37.5 mol % in the Na2O glass and P2O5≈40 mol % in the K2O glass), however, almost no increase of the density was found by an increase of Al2O3; the increases in the refractive index and chemical resistivity were also smaller than those in the glasses with a higher P2O5 content. The infrared absorption spectra of the glasses varied also with the P2O5 content. These changes in the properties are due to a marked structural difference between the glasses with a higher P2O5 content and those with a lower P2O5 content, and are also associated closely with the structural role of Al3+ ions in the glass.
Phase-transfer Reactions Catalyzed by Phosphoric Triamides Containing Hydrophobic Groups
Authors: Tomoi Masao , Hasegawa Takashi , Ikeda Manabu , Kakiuchi Hiroshi 
Published: July 2006

Abstract
Aqueous organic two-phase reactions (halogen exchange, cyanation, and borohydride reduction) have been catalyzed by phosphoric triamides containing hydrophobic groups. The phosphoric triamides, which have a high cation binding ability, exibited high catalytic activity for the two-phase reactions. The catalytic activity of N-alkylteramethylphosphoric triamides (1) was higher than that of the corresponding pentamethyl derivatives and the difference has been explained in terms of the contribution of the dimeric species of 1 and/or hydrogen bonding between the NH of 1 and the anionic moieties of inorganic reagents.
α,β-Unsaturated Carboxylic Acid Derivatives. XVII. The Facile Synthesis of Ethyl α-Azido-α-alkenoates and Reduction to Ethyl α-Amino-α-alkenoates
Authors: Shin Chung-gi , Yonezawa Yasuchika , Unoki Kazuo , Yoshimura Juji 
Published: July 2006

Abstract
Several pathways leading to ethyl α-azido-α-alkenoates (8) by the β-elimination to ethyl α-azido-β-substituted (hydroxy-, acetoxy-, or mesyloxy)-alkanoates with NaN3 or Et3N have been examined. The optimized procedure, in combination with subsequent reduction provides a general synthetic route to α-amino-α-alkenoic acid esters (9). The configuration of 8 and 9 have been shown to be of (Z)-geometry.