bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation, Optical Resolution, Racemization, and Ligand Isotopic Exchange of Tris(1,3-diphenyl-1,3-propanedionato)germanium(IV) Perchlorate in Acetonitrile
Authors: Ueno Fumio B , Nagasawa Akira , Saito Kazuo 
Published: July 2006

Abstract
Tris(1,3-diphenyl-1,3-propanedionato)germanium(IV) [Ge(bzbz)3]+ was prepared as crystalline perchlorate, and resolved by the crystallization of its salt with hydrogen (R,R)-O,O-dibenzoyltartrate. The patterns of UV and circular dichroism spectra are very similar to those of [Si(bzbz)3]ClO4. The racemization of the Δ-[Ge(bzbz)3]ClO4 was studied kinetically in acetonitrile at 40–60 °C to find the rate law: Rate=krac[complex], where krac=9.86×10−5 s−1 at 50 °C. The activation parameters (ΔH\eweq=99±2 kJ mol−1 and ΔS\eweq=−17±2 J K−1 mol−1) are very similar to those of tris(acetylacetonato)germanium (IV) complex. Compared with the rate of ligand isotopic exchange, the racemization should proceed via intramolecular mechanism. The steric effect coming from the substituents on the chelate ring should play an important role in determining the racemization rate.
Phase Relation in the System PbO–PbGeO3
Authors: Hirota Kazushi , Sekine Toshimori 
Published: July 2006

Abstract
Phase relations in the system PbO–PbGeO3 were determined using both the quenching and DTA techniques. Two new lead germanate phases Pb5GeO7 and Pb11Ge3O17 were found to be stable. It was found that the Pb5GeO7 melts incongruently at 738 °C to PbO plus liquid, whereas the Pb11Ge3O17 decomposes into Pb5GeO7 plus Pb3GeO5 at 728 °C. The compounds Pb3GeO5, Pb5Ge3O11, and PbGeO3 were identified as congruently melting compounds, in accordance with previous investigations. Some other compounds, such as Pb6GeO8, Pb4GeO6, and Pb3Ge2O7, which have been reported previously could not be confirmed as stable phases.
Preparations and Characterization of Cycloruthenated Complexes Derived from 1-Phenylpyrazole, 2-Phenylpyridine, and Benzo[h]quinoline
Authors: Hiraki Katsuma , Obayashi Yayoi , Oki Yoko 
Published: July 2006

Abstract
A pale yellow solution, prepared from RuCl3·3H2O and carbon monoxide in 2-methoxyethanol, reacted with 1-phenylpyrazole (Hphpz), 2-phenylpyridine (Hphpy), and benzo[h]quinoline (Hbzqn) to give new chlorobridging dinuclear cycloruthenated complexes, [{RuCl(C∼N)(CO)2}2] (C∼N=cycloruthenated moiety). These complexes reacted with Tl(acac) (acac=acetylacetonato ligand), γ-picoline (pic), and triphenylphosphine resulting in the break-down of the chloro-bridging bond of the complexes, and afforded new mononuclear cycloruthenated complexes, [Ru(acac)(C∼N)(CO)2], [RuCl(C∼N)(CO)2(pic)], and [RuCl(C∼N)(CO)n-(PPh3)3−n] (n=2 for phpz, and n=1 for phpy and bzqn), respectively. The complexes prepared in this study were characterized by IR, 1H-NMR, and mass spectroscopies.
The Absolute Configuration and Circular Dichroism of (+)240CD-[(2S,7S)-2,7-Dimethyl-3,6-diazaoctane-1,8-diamine]platinum(II) Chloride Dihydrate
Authors: Nakayama Yasuji , Ooi Shun’ichiro , Kuroya Hisao 
Published: July 2006

Abstract
The title compound was synthesized and characterized by means of absorption, circular dichroism, and its NMR spectra as well as X-ray structure analysis. The crystals are monoclinic, with a P21 space group, a=9.175(3), b=12.423(5), c=7.434(3) Å, β=108.1(4)°, and Z=2. The structure was determined from the diffractometcr data and refined by a least-squares method to R=0.041 for 1732 observed reflections. The Pt atom has an essentially planar coordination with 4 N atoms. The disposition of the four donor atoms is not rectangular, but trapezoidal; it is, moreover, slightly tetrahedral. The quadridentate ligand forms three 5-membered chelatc rings with the Pt atom. The two terminal rings are of a δ asymmetric envelope conformation, while the middle ring has a λ symmetric skew conformation. Both of the secondary N atoms possess a R configuration. The complex ion has a pseudo-two-fold axis by which the two terminal rings are related to each other. The circular dichroism spectrum reflects mainly the conformations of the 5-membered chelate rings. The features of the absorption and circular dichroism spectra are discussed on the basis of the geometry of the PtN4 chromophore.
Temperature Dependence of the Optical Resolution and Solubility Isotherm of Bis(ethylenediamine)oxalatocobalt(III) (1R,3S,4S,7R)-3-Bromocamphor-9-sulfonate
Authors: Fuyuhiro Akira , Yamanari Kazuaki , Shimura Yoichi 
Published: July 2006

Abstract
The determination of solubility isotherm of a ternary system, Λ-[Co(ox)(en)2](d-C10H14OBrSO3)–Δ-[Co(ox)(en)2](d-C10H14OBrSO3)–H2O, between 5 and 25 °C, revealed that the resolving agent (1R,3S,4S,7R)-3-bromocamphor-9-sulfonate ion is applicable to the optical resolution of the [Co(ox)(en)2]+ ion below 19 °C from the viewpoint of solubility in water, in spite of the formation of a pseudo racemic compound, Λ-[Co(ox)(en)2]·Δ-[Co(ox)(en)2] (d-C10H14OBrSO3)2·2H2O.
The Regioselective C-Hydroxyalkylation of 1,3-Diphenyl-1,3-propanedione with Halo Alcohols, Involving Intramolecular Alcoholysis: the Synthesis of Oxoalkyl Esters
Authors: Tsutsumi Hideo , Inoue Kimio , Ishido Yoshiharu 
Published: July 2006

Abstract
The reaction of 1,3-diphenyl-1,3-propanedione (1) with 2-chloroethanol (2) or 3-chloro-1-propanol (3) was performed in the presence of potassium carbonate and sodium iodide as an improved procedure for regioselective C-hydroxyalkylation, involving intramolecular alcoholysis; the effects of the solvents, the temperature, and the amounts of potassium carbonate and sodium iodide were also investigated. The reaction with 2 afforded 3-benzoylpropyl benzoate (4) (ca. 70% yield), together with 2-benzoylmethyl-2-phenyl-1,3-dioxolane (5) (ca. 15% yield). The reaction with 3, on the other hand, gave 4-benzoylbutyl benzoate (92–94% yield); the corresponding 1,3-dioxane derivative was detected only in a trace. Moreover, the reaction of 1 with 2-hydroxyethyl tosylate was similarly performed, but the yields of both 4 and 5 were unexpectedly low.
Michael Addition of 4H-Cyclopenta[def]phenanthrene to 9,9′-Bifluorenylidene and the Related Reactions
Authors: Kimura Takao , Minabe Masahiro , Suzuki Kazuo 
Published: July 2006

Abstract
The compound 9-(4H-cyclopenta[def]phenanthren-4-yl)-9,9′-bifluorene was synthesized by the Michael addition of 4H-cyclopenta[def]phenanthrene to 9,9′-bifluorenylidene and also by other reactions. In addition, five kinds of trimers which consisted of 4H-cyclopenta[def]phenanthrene and fluorene were obtained by the same reactions. The conformation of these trimers is assigned to be the gauche-gauche form.
The Total Synthesis of (+)-Totarol and (+)-Podototarin
Authors: Matsumoto Takashi , Suetsugu Akira 
Published: July 2006

Abstract
The Grignard reaction of 7-methoxyphthalide with methylmagnesium iodide, followed by acetylation and dehydration, gave 3-acetoxymethyl-2-isopropenylanisole which, on catalytic hydrogenation, afforded 3-acetoxymethyl-2-isopropylanisole. This was then converted into (2-isopropyl-3-methoxybenzyl)triphenylphosphonium chloride (8) via 3-hydroxymethyl-2-isopropylanisole and 3-chloromethyl-2-isopropylanisole. The Wittig reaction of (R)-(−)-α-cyclocitral with 8 in the presence of butyllithium afforded the corresponding styryl derivative, which was converted into the dihydro compound (19) by partial catalytic hydrogenation. The intramolecular cyclization of 19 gave (+)-totaryl methyl ether (20) along with its cis-isomer. The methyl ether 20 was finally demethylated with boron tribromide to give (+)-totarol (1), which was further characterized as its acetate. Since the conversion of (+)-1 into (+)-podototarin has already been reported, the present work can be regarded as the total synthesis of natural (+)-podototarin.
The Total Synthesis of (+)-Taxoquinone, (−)-7α-Acetoxyroyleanone, (−)-Dehydroroyleanone, (−)-Horminone, (−)-7-Oxoroyleanone, and (+)-Inuroyleanol
Authors: Matsumoto Takashi , Harada Shogo 
Published: July 2006

Abstract
Methylation of 12-benzoyloxyabieta-8,11,13-trien-11-ol with methyl iodide afforded 11-benzoyloxy-12-methoxyabieta- and 12-benzoyloxy-11-methoxyabieta-8,11,13-triene (9). Oxidation of the latter product with chromium trioxide, followed by sodium borohydride reduction and acetylation, gave 7β-acetoxy-12-benzoyloxy-11-methoxyabieta-8,11,13-triene (17) and its 7α-acetoxy isomer (18) in a ratio of ca. 5 : 1. On the other hand, treatment of 9 with lead tetraacetate produced 17 and 18 in a ratio oi ca. 1 : 2. The 7β-acetate (17) was then oxidized with chromium trioxide and the resulting p-quinone derivative was hydrolyzed with aqueous sodium hydroxide to give taxoquinone (1), which on dehydration gave dehydroroyleanone. Similarly, the 7α-acetate (18) was converted into horminone (4) via the p-quinone derivative, which was treated with aqueous sodium hydrogencarbonate to give 7α-acetoxyroyleanone. Oxidation of 4 with manganese dioxide afforded 7-oxoroyleanone. Methylation of 1 with diazomethane, followed by oxidation with a chromium trioxide-pyridine complex, afforded 12-methoxyabieta-8,12-diene-7,11,14-trione, which on reduction with sodium dithionite gave inuroyleanol.
Kinetics of the Reaction of α-Chloro Aliphatic Acids with Aqueous Ammonia
Authors: Ogata Yoshiro , Kawasaki Atsushi , Sawaki Yasuhiko , Yamauchi Yuya 
Published: July 2006

Abstract
The kinetics of the reaction of α-chloro aliphatic acids (CAA’s) with aqueous ammonia to form the corresponding α-amino acids and α-hydroxy acids have been studied by measuring the produced chloride ion. The observed rate for CAA’s having COOH on a s-C (s-CAA’s) is expressed as: v=(k1+k2[NH3]ex)[CAA], while the rate for CAA having COOH on a t-C (t-CAA): v=k1[CAA], These results together with previous observations indicate that the mechanism changes with substrate, i.e., pure SN2 type for chloroacetic acid to pure SN1 type for α-chloroisobutyric acid. The exclusion of α-lactone mechanism and the effect of carboxylato group are discussed. The reactivity of ammonia toward α-chloro aliphatic acids is as twice as that of hydroxide ion.
Solvolysis in Carboxamides. V. Solvolytic Elimination of threo-1-Methyl-2-phenylpropyl Brosylate in N,N-Dimethylacetamide. Kinetic, Product, and Deuterium Tracer Studies
Authors: Saito Seiki , Doihara Kenji , Moriwake Toshio , Okamoto Kunio 
Published: July 2006

Abstract
Solvolysis of a series of ring substituted threo-1-methyl-2-phenylpropyl brosylates has been carried out in N,N-dimethylacetamide (DMA) as solvent. Hammett treatment of the rate data indicated that the DMA solvolysis of the unsubstituted brosylate (1c) falls into the category of ks pathway (100%). In order to gain further information of the nature of the ks pathway, the DMA solvolysis of 1c or 1c-2-d (labeled at C(2)) has been conducted. The product distribution, effect of water content on it, the composition and deuterium distribution of recovered brosylate, kinetic isotope effect, and the deuterium distribution of product have been investigated. The products consisted of the olefins ((E)- and (Z)-2-pheny1-2-butenes, and 2- and 3-phenyl-1-butenes), and, in the presence of water in DMA, the carboxylates (erythro- and thero-1-methyl-2-phenylpropyl acetates) and the small amount of diastereomeric alcohols. The major product was (Z)-2-phenyl-2-butene, indicating the occurrence of anti-E1 process. The deuterium was substantially scrambled in each product. These findings suggest that the reaction proceeds through tight ion-pair and subsequent processes such as anti-E1, 2,1-phenyl and -hydride shifts, solvent capture, and threo-erythro interconversion take place competitively. In view of a substantial extent of intervention of such rearrangement, the involvement of nucleophilic solvent assistance is thought to be less probable in this ks process.
Studies on Unusual Amino Acids and Their Peptides. X. The Convenient Synthesis of t-Leucine and the Optical Resolution of the N-Benzyloxycarbonyl Derivative
Authors: Miyazawa Toshifumi , Takashima Katsumi , Mitsuda Yoshikazu , Yamada Takashi , Kuwata Shigeru , Watanabe Hiroshi 
Published: July 2006

Abstract
t-Leucine has been conveniently prepared on a large scale from the phenylhydrazone of trimethylpyruvic acid, which was readily obtained as a precipitate from the oxidation of pinacolone. The N-benzyloxycarbonyl derivative of Dl-t-leucine has been resolved with quinine and quinidine in ethanol.
Effect of Etching on Intrinsic and Dye-sensitized Photocurrents in Zinc Oxide Electrodes
Authors: Matsumura Michio , Nomura Yoichi , Tsubomura Hiroshi 
Published: July 2006

Abstract
The photoelectrochemical behavior of sintered zinc oxide electrodes was studied. The intrinsic photocurrent, generated by ultraviolet illumination of the zinc oxide electrode, significantly diminished by grinding the electrode surface with an abrasive, and was restored by etching in 2 M(M= mol dm3)HCl for ca. 120 s. The dye-sensitized photocurrent caused by rose bengal was also lowered by grinding, but the effect was not as large as in the case of the intrinsic photocurrent, and the photocurrent was restored in a much shorter time of etching. The dye-sensitized photocurrent for an insufficiently etched electrode was enhanced by addition of a reducing agent, e.g., hydroquinone or allylthiourea. However, no enhancement was observed for a well etched electrode. The results, together with the luminescence and reflection spectra of zinc oxide, were discussed by means of models for the semiconductor electronic bands.
Direct Synthesis of 2,2-Diaryl-3-methyl-2,3-dihydrobenzothiazoles from 3-Methyl-2,3-dihydrobenzothiazole-2-thione and Some Mechanistic Aspects
Authors: Akiba Kin-ya , Shiraishi Hiroaki , Inamoto Naoki 
Published: July 2006

Abstract
Reactions of 3-methyl-2,3-dihydrobenzothiazole-2-thione (1) and 3-methyl-2-(methylthio)benzothiazoliumiodide with Grignard reagents gave 2,2-disubstituted 3-methyl-2,3-dihydrobenzothiazole (2) as a major product as well as 2,2′-disubstituted 3,3′-dimethyl-2,2′,3,3′-tetrahydrobi(2-benzothiazolyl) (3). Reactions of 1 with organolithiums gave 2 as a major product. The results demonstrate that the formation of 3 is due to the presence of transition metals as an impurity in magnesium.
Association and Photolysis of 1-Benzyl-4-methoxycarbonylpyridinyls
Authors: Ikegami Yusaku , Kubota Shozo , Watanabe Hidetoshi 
Published: July 2006

Abstract
1-Benzyl- and 1-(4-methylbenzyl)-4-methoxycarbonylpyridinyl radicals have been prepared by reducing the corresponding pyridinium iodides with sodium amalgam. Hyperfine structures of the ESR spectra were analyzed. The radicals were decomposed photochemically with visible light in the region 380–440 nm in order to generate the intermediate benzyl radicals which were identified spectroscopically at 77 K. Association of each radical at low temperature forms a diamagnetic radical dimer, which is transformed by irradiating the solution with 440–470 nm light into the triplet dimer with zero-field parameters, D=ca. 0.017 cm−1 and E≈O. Another radical, 1-(4-nitrobenzyl)-4-methoxycarbonylpyridinyl, is unstable at room temperature.
Anodic Oxidation of N,N-Dimethyl-m-toluidine at a Platinum Electrode in an Acetonitrile Solution
Authors: Yasukouchi Kazuo , Taniguchi Isao , Yamaguchi Hiroko , Tanoue Tatsuya 
Published: July 2006

Abstract
The electrochemical behavior of N,N-dimethyl-m-toluidine (DMMT) in an acetonitrile solution at a Pt electrode was investigated. By controlled-potential oxidation at 0.65 V (vs. Ag/0.01 mol dm−3 AgClO4), the dihydro compound (I-a), which had been considered to be an intermediate in the reaction forming benzidine, was probably obtained. I-a was gradually converted to N,N,N′,N′-tetramethyl-2,2′-dimethylbenzidine (TMMB) in the solution within several hours. I-a was easily converted to TMMB by the cathodic re-reduction at −0.9 V or by adding either pyridine or water; this reaction pathway is useful for the synthesis of TMMB. Preliminary mechanistic information on the anodic oxidation of DMMT is also given by cyclic and ring-disk electrode voltammetry, current-reversal chronopotentiometry, and controlled-potential coulometry. The proposed reactions are: A–e→A\underset.+, A\underset.++A\oversetk→A-A\underset.+, and A-A\underset.+–e→DH22+, where A and A\underset.+ are, respectively, DMMT and its cation radical, DH22+ is the dihydro compound (I-a), and k is the rate constant of the coupling reaction (ca. 5×103 dm3 mol1 s1). TMMB is formed by: DH22++2e(or 2Py)→D+H2(or 2PyH+), where D is TMMB and Py is pyridine.
HeI and HeII Photoelectron Study of N2O4
Authors: Nomoto Katsunori , Achiba Yohji , Kimura Katsumi 
Published: July 2006

Abstract
A 304 Å HeII photoelectron spectrum of N2O4 in the gaseous phase has been deduced in the region up to 29 eV from a HeI spectrum of NO2–N2O4 mixture obtained with a nozzle beam technique, indicating three new maxima in the region between 20 and 29 eV. A 584 Å Hel spectrum of N2O4 was also obtained here. From a comparison of the HeI and HeII spectra of N2O4 below 20 eV, it was confirmed that two ionization bands exist at 16.5 and 18.2 eV which appear as shoulders in the HeII spectrum. At least fourteen ionization bands have been identified from the HeII spectrum in the region studied. The thirteen bands below 24 eV have been assigned on the basis of a recent Green’s function study of von Niessen et al.
Dry Ozonation of Friedelane and Friedelin
Authors: Akiyama Eri , Tada Masahiro , Tsuyuki Takahiko , Takahashi Takeyoshi 
Published: July 2006

Abstract
Dry ozonation of friedelane afforded 18β,19β-epoxyfriedelane, 19-oxofriedelane, 16-oxofriedelane, 21-oxofriedelane, friedelin, and a new compound, 15-oxofriedelane. Friedelin, on dry ozonation, gave 3,16-dioxofriedelane, 3,19-dioxofriedelane, and new compounds, 18β,19β-epoxyfriedelan-3-one and 3,15-dioxofriedelane. It was shown that the oxidation occurred at D and E rings regioselectively in the dry ozonation.
Complexation Equilibria of Vanadium(V) with 8-Quinolinolate in Aqueous Solutions
Authors: Yuchi Akio , Yamada Shinkichi , Tanaka Motoharu 
Published: July 2006

Abstract
The complexation equilibria of vanadium(V) with 8-quinolinolate ion(ox−) were investigated spectrophotometrically. Depending upon the acidity of the solution various 1 : 1 and 1 : 2 complexes are formed: VO3ox2−, VO3Hox−, VO2ox, and VO2ox2−. The formation and protonation constants of these complexes are discussed in terms of their structures.
Circular Dichroism and Stereochemistry of Tetranuclear Cobalt(III) Complexes of Hexol Type. I. Dodecaammine-hexa-μ-hydroxotetracobalt(III) Ion, [Co{(OH)2Co(NH3)4}3]6+
Authors: Kudo Tomikatsu , Shimura Yoichi 
Published: July 2006

Abstract
From the circular dichroism spectra of optically active dodecaammine-hexa-μ-hydroxo-tetracobalt(III) ion, (+)589-[Co{(OH)2Co(NH3)4}3]6+, measured in the visible and ultraviolet region in several solvents such as 0.01M-HCl and 0.17M-Na2SeO3, the d–d transitions of the complex are assigned in consideration of the ion-pairing effect. The absolute configuration of (+)589 isomer is assigned as Δ based upon a negative sign of the Ea component for the CoO6 chromophore. The circular dichroism change by the ion-pairing is attributed to the vicinal effect of chiral oxygen centers stereospecifically produced by the ion-pair formation, and the importance of the oxygen chirality is discussed on the basis of the time-course of circular dichroism change in the solutions.
Synthesis of a Protected Tridecapeptide Corresponding to Positions 17–29 of Human Lysozyme
Authors: Yoshimura Shoko , Shimonishi Yasutsugu 
Published: July 2006

Abstract
For a semi-synthesis of human lysozyme by coupling its natural fragment with synthetic peptides, a protected tridecapeptide corresponding to positions 17–29 of the enzyme was prepared from three protected peptide fragments (II, VI, and XI) by the conventional method in pure form on the basis of analyses.
Syntheses of Capreomycin Analogs in Relation to Their Antibacterial Activities
Authors: Nomoto Shinya , Shiba Tetsuo 
Published: July 2006

Abstract
Six analogs of an antituberculous antibiotic capreomycin were synthesized in order to clarify the structure-activity relationship, especially with regard to the significance of the β-amino group in α,β-diaminopropionic acid residue as well as the position of linkage of the branch residue, β-lysine, to the cyclic peptide moiety. All the synthetic products were found to have the same conformations in solution as those of the natural antibiotics in terms of NMR spectra. It was found from their antibacterial activities that an amino group located at β-position of the α,β-diaminopropionic acid residue adjacent to ureidodehydroalanine residue remarkably strengthens the biological activity, and that the position of a branch does not significantly influence the antibacterial potency.
Preparation of Model Polymers for Visual Pigment and Spectral Changes
Authors: Nanasawa Masato , Kamogawa Hiroyoshi 
Published: July 2006

Abstract
N-(8′-Apocarotene-8′-ylidene)butylamine (Bu-SB) has been protonated with amino acid derivatives in aqueous solution and the absorption maxima of the protonated products observed at 500 nm. Copolymers (from Nα-methacryloyl-l-lysine methyl ester and α-methyl N-methacryloyl-l-glutamate) bearing long conjugated double bonds as a side chain have been synthesized for the simulation of rhodopsin. The absorption spectra shifted to longer wavelengths, and the absorbances amounted to 4–8%, based on the maximum peaks.
The Regioselective Amino-exchange Reaction of β-Amino Conjugated Enones
Authors: Kashima Choji , Yamamoto Yasuhiro 
Published: July 2006

Abstract
By heating with various amines, the amino-exchange reaction of β-amino conjugated enones was regioselectively accomplished on β-carbon to give the corresponding β-amino conjugated enones. The resulting β-dialkylamino conjugated enones could then be used for the synthesis of β,β-disubstituted conjugated enones by treatment with Grignard reagents.
The Hydrogen-transfer Reaction of a Diazo Compound Catalyzed by a Cobalt Complex
Authors: Yoshino Kenji , Ohkatsu Yasukazu , Tsuruta Teiji 
Published: July 2006

Abstract
Acetophenone α-methylbenzylhydrazone was produced by the thermolysis of 1,1′-diphenylazoethane in the presence of a cobalt complex in benzene. In this reaction, the cobalt complex seemed to stabilize the radicals formed from the azo compound by the elimination of α-hydrogen. The stabilized radicals underwent 1,3-rearrangement to form acetophenone α-methylbenzylhydrazone. The driving force of this rearrangement is considered to be the nature of the cobalt atom, which prefers a bond formation with a more electronegative nitrogen atom to a carbon atom.
Temperature Effects on the Stereochemistry of the Solvolysis of trans-2,3-Diphenyloxirane
Authors: Inoue Masashi , Taguchi Yoshio , Sugita Toshio , Ichikawa Katsuhiko 
Published: July 2006

Abstract
The temperature effects on the stereochemistry of the acid-catalyzed ethanolysis of trans-2,3-diphenyloxirane were examined. The stereochemistry of the reaction became more retentive as the reaction temperature was raised. The reaction mechanisms are discussed, and it is concluded that concurrent reactions take place in the ethanolysis, one of them giving an inverted product, and the other, a retained one, and that the former reaction is caused by a nucleophilic attack of ethanol on the carbon of the conjugate acid of the epoxide, while the latter proceeds via an intermediate which has a carbonium-ion character.