bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structure and Absolute Configuration of α-Pompene. II. An X-Ray Analysis of the Mono p-Bromobenzoate of the Diol Derived from α-Pompene
Authors: Nozaki Hiroshi , Matsuo Akihiko , Nakayama Mitsuru , Kushi Yoshihiko , Kamijo Nagao , Hayashi Shûichi 
Published: July 2006

Abstract
The mono p-bromobenzoate of the diol derived from α-pompene has been studied by X-ray crystal structure analysis and determined to be 9-p-bromobenzoxy-8-hydroxy-1,2,6,8-tetramethyltricyclo[5.3.1.02,6]undecane. The crystals are of the orthorhombic space group P212121, a=46.53(2), b=12.20(2), c=7.39(2) Å, Z=8, and hence there are two independent molecules per asymmetric unit. The structure was solved by the heavy-atom methods, and refined by block-diagonal least-squares calculations to a final R value of 0.103 for 2493 observed reflections. The structures of the two independent molecules in the asymmetric unit are quite similar. Both molecules contain a tricyclo[5.3.1.02,6]undecane ring in which three fused rings (cyclohexane, cyclopentane, and cyclopentane) are present. The overall configuration of these three fused rings can be described as a “cis” type. The conformation of the cyclohexane ring is of a chair form, and the two cyclopentane rings exhibit envelope forms. Based on the anomalous X-ray dispersion effect of the bromine atoms, the absolute configuration of the title compound was also determined.
The Substituent Effect. XIII. Solvolysis of 1-(7-Substituted 2-Fluorenyl)ethyl Chlorides and Alkaline Hydrolysis of Ethyl 7-Substituted 2-Fluorenecarboxylates
Authors: Tsuno Yuho , Tairaka Yoshihiko , Sawada Masami , Fujii Takahiro , Yukawa Yasuhide 
Published: July 2006

Abstract
Two sets of rate constants for (i) solvolysis of 1-(7-substituted 2-fluorenyl)ethyl chlorides in both 90 and 80% aqueous acetone and (ii) alkaline hydrolysis of ethyl 7-substituted 2-fluorenecarboxylates in 85% aq EtOH have been determined. Both substituent effects could be correlated excellently with the LArSR relationship; the resulting r+ values (0.82 and 0.47, respectively) were comparable with the r+’s in the corresponding biphenylyl system under the same conditions. The comparison of ρπ+ values clearly indicates a more efficient transmission of the pi-electronic effect in the fluorenyl than in the biphenylyl ststem (1:0.75). This can be attributed to a factor of twisting in the latter pi-system. The attenuation of the transmission of the Pi effect was found to be characteristic of the intervening pi-systems independent of reactions: 1.00(4-X-1-phenyl), 0.55(6-X-2-naphthyl), 0.35(7-X-2-fluorenyl), and 0.25(4′-X-4-biphenylyl).
Kinetic Studies on the Lime Sulfurated Solution (Calcium Polysulfide) Process for Removal of Heavy Metals from Wastewater
Authors: Yahikozawa Kiyochika , Aratani Toshiro , Ito Ryuzo , Sudo Takataro , Yano Takeo 
Published: July 2006

Abstract
A new process has been developed for wastewater purification, utilizing “Lime Sulfurated Solution” as a coagulant. Calcium polysulfide, the main component of this solution, decomposes in water on contact with a gas (atmospheric air or CO2 gas) and reacts with heavy metals. The heavy metals are removed as practically insoluble precipitates. The kinetics of this process were studied in a batch stirred tank vessel to obtain the fundamental data needed for development of a commercial continuous process. The findings are as follows: (1) Processing of bivalent metals Hg2+, Cd2+, Zn2+, Pb2+, and Cu2+ are completed in a few minutes to achieve the water quality standards in Japan. (2) Cr3+ is flocculated as Cr(OH)3 by the strong alkaline base of CaSx solution. It takes about 60 minutes for the precipitation with CO2 blowing, and 30 min with aeration. Cr(VI) is quickly reduced to Cr3+ and removed as Cr(OH)3. (3) A simulated wastewater simultaneously contaminated with 6 kinds of heavy metals can be brought well within the standards within 20 min of processing time.
The Solvent Extraction of Thallium(I) as a Dibenzo-18-crown-6 Complex with the Picrate Ion
Authors: Sekine Tatsuya , Wakabayashi Hiroji , Hasegawa Yuko 
Published: July 2006

Abstract
The solvent extraction of thallium(I) with dibenzo-18-crown-6 (DBC) as the picrate into chloroform and benzene was measured at 25 °C. The extraction was nearly the same as that of potassium(I) and much better than rubidium(I); this tendency was mainly attributed to the difference in the stability of the DBC complexes in the aqueous phase. Thallium(III) was extracted only poorly.
The Derivation of a Brominated Algal Component from Myrcene
Authors: Yoshihara Kazuo , Hirose Yoshio 
Published: July 2006

Abstract
The supposed structure, 5-bromo-4,4-dimethyl-2-vinyl-1-cyclohexene, for a brominated monoterpene from Desmia (Chondrococuus) hornemanni was derived from myrcene through a one-step reaction, and the structure was confirmed.
Solvent Extraction Equilibria of Acids. VI. The Extraction of Several Mono- and Dicarboxylic Acids with Trioctylphosphine Oxide in Hexane
Authors: Niitsu Masaru , Sekine Tatsuya 
Published: July 2006

Abstract
The solvent extraction equilibria of acetic, propionic, and butyric acid and mono-, di-, and trichloroacetic acid (HA), as well as those of oxalic, malonic, succinic, glutaric, and adipic acid (H2A), have been determined in liquid–liquid systems of hexane containing none or a certain amount of trioctylphosphine oxide (E) and an aqueous 1 mol dm3 chloride solution at 25°C. The constants, Kd=[HA]org/[HA], Kdim=[(HA)2]org/[HA]org2, Kex1′=[HAE]org/[HA][E]org, Kex2′=[H2AE2]org/[H2A][E]org2, and β1(org)=[HAE]org/[HA]org[E]org2, have then been determined from the data. It was found that, among the three fatty acids, the value of Kex1′ was higher as the chain length increased, but the values of β1(org) were nearly all the same, while among the chloroacetic acids they were higher as the number of chloride atom increased. The extraction of the dicarboxylic acids with E was not very different, although the number of the –CH2– between the two carboxyl groups changed from zero to four.
Photochemical Oxidation of Benzene, Toluene, and Ethylbenzene Initiated by OH Radicals in the Gas Phase
Authors: Hoshino Mikio , Akimoto Hajime , Okuda Michio 
Published: July 2006

Abstract
Photochemical oxidation of benzene, toluene, and ethylbenzene initiated by OH radicals in the presence of NO and NO2 was studied in the air by using a 67 dm3 reaction chamber made of Pyrex glass. OH radicals were produced by photochemical decomposition of nitrous acid, the products being phenol and nitrobenzene for benzene; cresols, benzaldehyde, m- and p-nitrotoluenes, and benzyl nitrate for toluene; ethylphenols, benzaldehyde, acetophenone, and m- and p-nitroethylbenzene for ethylbenzene. The reaction mechanisms are proposed based on the addition of OH radicals to aromatic rings and the hydrogen abstraction of OH radicals from alkyl groups.
Syntheses of Unsymmetrical Sulfides and Bis(alkylthio)methanes from Diphenylphosphinodithioate Esters
Authors: Goda Koshiro , Hanafusa Fumito , Inamoto Naoki 
Published: July 2006

Abstract
Unsymmetrical sulfides were prepared by the reactions of diphenylphosphinodithioate esters with organolithiums in tetrahydrofuran (THF) at −78 °C or at room temperature in fairly good or excellent yields. Similarly, methylene bis(diphenylphosphinodithioate) gave bis(alkylthio)methanes by reactions with organolithiums in good yields. The use of bad-smelling thiols is avoided and the phosphorus part can be recycled after sulfurization and esterification. Allyl diphenylphosphinodithioate gave allylbenzene via SN2(C) reaction upon treatment with phenylmagnesium bromide in refluxing THF.
Chemical Studies on Tuberactinomycin. XIV. Novel Synthesis of Dl-Capreomycidine
Authors: Wakamiya Tateaki , Mizuno Katsutoshi , Ukita Tatsuzo , Teshima Tadashi , Shiba Tetsuo 
Published: July 2006

Abstract
Cyclic guanidino amino acid, capreomycidine, is a component of antituberculous peptides, capreomycin and tuberactinomycin N and O. Its epimer was also found in protease inhibitors, chymostatin and elastatinal. A new synthetic approach to Dl-capreomycidine via β-hydroxyornithine was studied for the purpose of total synthesis of capreomycidine and epicapreomycidine of natural forms or its hydroxy derivative, tuberactidine.
Biosynthesis of Aloenin in Aloe arborescens var. natalensis
Authors: Suga Takayuki , Hirata Toshifumi 
Published: July 2006

Abstract
The 14C- and 3H-labeling patterns in aloenin biosynthesized by uptake of acetate-1-14C, malonate-2-14C, phenylalanine-1-14C and -3-14C, methionine-methyl-14C, and glucose-3-3H to Aloe arborescens var. natalensis demonstrated that the carbon skeleton of aloenin is arisen via a biological polyketide by the acetate-malonate pathway and the O-methyl group originates from methionine. Further, feeding experiments of 3H/14C-doubly labeled 4-methoxy-6-(2,4-dihydroxy-6-methylphenyl)-2-pyrone and 5-(2-β-d-glucopyranosyloxy-4-hydroxy-6-methylphenyl)-3,5-dioxopentanoic acid in the Aloe plant revealed that an immediate intermediate is the pyrone derivative and not the dioxopentanoic acid derivative. Aloenin was demonstrated to be biosynthesized in such a way that the first formation of the pyrone by cyclization of the biological polyketide and then O-methylation of the cyclized intermediate is followed by introduction of a glucose molecule into the pyrone derivative.
New Methods for the Preparation of 3-Substituted Furans
Authors: Inomata Katsuhiko , Aoyama Shin-ichi , Kotake Hiroshi 
Published: July 2006

Abstract
It was found that ethyl 4,4-dimethoxy-2-(phenylthio)butyrate and 3-tosylpropanal ethylene acetal are useful starting materials for the preparation of 3-substituted furans. Several 3-substituted furans, including dendrolasin [3-(4,8-dimethyl-3,7-nonadienyl)-furan], were prepared by the reaction of these compounds with alkyl halides in good yields.
Critical Micelle Concentration Reduction of Aqueous Sodium Dodecyl Sulfate Solutions upon the Addition of Alcohols
Authors: Hayase Kohji , Hayano Shigeo 
Published: July 2006

Abstract
Linear relations were found between the critical micelle concentration (CMC) reduction and the carbon number of the alcohols added both at 313.15 K and 328.15 K. The slopes of the CMC reduction against the carbon number of the alcohols are almost the same at 298.15, 313.15, and 328.15 K.
A-Substituted 5β-Steroids. IX. Preparation of 5β-Cholest-1-ene and 2-ene from 2β-Bromo-5β-cholestan-3-one
Authors: Abe Kanji , Satoh J Yasuo 
Published: July 2006

Abstract
5β-Cholest-1-ene has been prepared from 2β-bromo-5β-chloestan-3-one. An alternative route to 5β-cholest-2-ene has also been developed by use of bromoketone. These olefins are less stable, being oxidized gradually by air to 5β-cholest-1-en-3-one at room temperature.
A Quinone and a Phenol from a Myrsinaceae Plant
Authors: Kusumi Takenori , Kakisawa Hiroshi , Chen Yuh-Pan , Lyn Jing-Ing , Hsu Hong-Yen 
Published: July 2006

Abstract
Ardisianone and ardisianol isolated from Ardisia quinquegona Blume were determined to be 2-(2-acetoxypentadecyl)-6-methoxy-1,4-benzoquinone and 4-acetoxy-2-(2-acetoxypentadecyl)-6-methoxyphenol, respectively.
Intramolecular Hydrogen Bond between Hydroxyl Group and π-Base in 2-Hydroxybiphenyl
Authors: Ioki Yoshikazu , Kawana Hiroko , Nishimoto Kichisuke 
Published: July 2006

Abstract
In order to clarify the nature of the intramolecular hydrogen bond between the hydroxyl group and the π-electron system in 2-hydroxybiphenyl, MO calculation based on the CNDO/2 MO method has been carried out. The total electronic energy of the molecule has been divided into one- and two-atomic terms. It was found that the resonance term mainly contributes to the intramolecular hydrogen bond formation. Contribution of other terms is discussed.
A Rate Study on the Oxidative Addition Reactions of Iodine toward Tetrakis(2,4,6-trimethylphenyl and t-butyl isocyanide)rhodium(I) Perchlorates
Authors: Kuwae Ryosho , Tanaka Toshio 
Published: July 2006

Abstract
The reaction of [RhL4]ClO4 (L=2,4,6-Me3C6H2NC and t-BuNC) with an equimolar amount of iodine yields a trans adduct, [RhI2L4]ClO4. The rate of this reaction in acetonitrile was measured employing a stopped-flow technique under pseudo-first-order conditions with excess iodine. The result indicates that the reaction proceeds via an intermediate which is presumably assigned to cis-[RhI2L4]ClO4, followed by intramolecular isomerization to the trans adduct.
A Semi-empirical MO Study of Radical-induced Decomposition of Dibenzoyl Peroxide. The Charge-transfer Character and Reaction Mechanism
Authors: Kikuchi Osamu , Suzuki Keizo , Tokumaru Katsumi 
Published: July 2006

Abstract
Radical-induced decomposition reactions of diacyl peroxides were investigated on the basis of the electronic structure of the peroxide-radical systems which were calculated using an approximate restricted open-shell SCF MO method in the MINDO/3 approximation, and on the basis of configuration analysis of the transition state of the reaction. For the transition state, (1) the change in peroxy O–O bond length is expected to be small, (2) the odd-electron density on the leaving group of the SH2 displacement is expected to be very small, although appreciable odd-electron delocalization from the radical to the peroxide was observed, (3) the charge-transfer (CT) interactions which correspond to electron transfer from the radical to the peroxide was found to be important in the transition state. The trends observed in the orbital energies of the LUMO of substituted dibenzoyl peroxides and in the CT character of the transition state, which involves the singly-occupied MO of the radical and the 2pσ* MO of the peroxide, agree well with the experimental facts, and strongly support a previous postulate that an important role is played by the 2pσ* MO of the peroxy O–O group in the reaction.
Substituent Effects on 6-Substituted 3-Hydroxy-1-methyl-4-pyridones
Authors: Imafuku Kimiaki , Takahashi Kumio , Matsumura Hisashi 
Published: July 2006

Abstract
Acid dissociation constants and UV and NMR spectra of a series of 6-substituted 3-hydroxy-1-methyl-4-pyridones have been measured. The acid dissociation constants have been analyzed in terms of the Hammett equation to give linear relationships, with ρ=1.16 for the conjugate acids and ρ=1.06 for the neutral compounds. Halochromism in the UV spectra gave the equation: Δ\ ildeν=689 pKa−9399, and the Hammett plots of the chemical shifts of the 2-H, 5-H, and CH3 protons gave linear relationships, with ρ=1.78, 2.56, and 1.39, respectively.
Pseudo-sugars. 4. A Facile Synthesis of Dl-Validamine and Its Derivative
Authors: Ogawa Seiichiro , Nakamoto Koji , Takahara Masaaki , Tanno Yoshio , Chida Noritaka , Suami Tetsuo 
Published: July 2006

Abstract
Penta-N,O-acetyl-Dl-validamine was prepared from readily available endo-2, exo-3-diacetoxy-endo-6-acetoxymethyl-7-oxabicyclo[2.2.1]heptane in three steps in an overall yield of 36%.
Carbon-Carbon Bond Formation by Use of Chloroiodomethane as a C1 Unit. I. Formation of Chloromethyltriphenylphosphonium Iodide, and Its Application for the Wittig Chloromethylenation of Aldehydes and Ketones
Authors: Miyano Sotaro , Izumi Yu , Fujii Katsuo , Ohno Yutaka , Hashimoto Harukichi 
Published: July 2006

Abstract
Chloromethyltriphenylphosphonium iodide has been prepared by the reaction of chloroiodomethane with triphenylphosphine. Upon treatment with potassium t-butoxide in t-butyl alcohol, the phosphonium iodide was converted into chloromethylenetriphenylphosphorane; this in turn was used for the Wittig reaction of aldehydes and ketones into the corresponding chloroolefins of the type RCH=CHCl and RR′C=CHCl in good to moderate yields. The configurations of these chloroolefins were assigned on the basis of NMR spectral studies. Direct conversion of benzaldehyde into phenylacetylene was also achieved using the phosphonium salt and excess potassium t-butoxide.
The Vibrational Spectra and Rotational Isomerism of 3-Butenylsilane
Authors: Taga Keijiro , Ohno Keiichi , Murata Hiromu 
Published: July 2006

Abstract
The infrared and Raman spectra of 3-butenylsilane, CH2=CHCH2CH2SiH3 (and –SiD3), were measured for the gaseous, liquid, and solid states. The fundamental vibrations were assigned, and the normal vibrations were calculated in relation to the rotational isomerism. The calculations indicated that the cis-trans (CT), skew-trans (ST), and skew-gauche (SG and SG′) forms coexist in the gaseous and liquid states, while the CT form only persists in the solid state. From the temperature variation in the Raman intensities, the stability of the molecular conformations was found to be in this order: CT\gtrsimST&gt;SG′&gt;SG in the liquid state, indicating that an appreciable interaction between the silicon atom and the C=C bond, such as in the case of allylsilane, is not present for 3-butenylsilane.
Transannular Interaction in the Excited Triplet States of [2.2]Paracyclophane and Related Compounds
Authors: Ishikawa Shun-ichi , Nakamura Junko , Iwata Suehiro , Sumitani Minoru , Nagakura Saburo , Sakata Yoshiteru , Misumi Soichi 
Published: July 2006

Abstract
The triplet-triplet absorption spectra of [2.2]paracyclophane and related cyclophanes (naphthalenophane, pyrenophane, and anthracenophane) were measured. Cyclophanes in which two component subunits fully overlap, show new bands together with monomer-like bands. The electronic structures of triplet states of these cyclophanes were studied theoretically by the “molecules in molecule” method, special attention being paid to the correlations of the electronic structures of cyclophanes with those of corresponding monomers and also to the dependences of the charge transfer interaction upon the overlapping between the component subunits and upon the molecular size.
On the Phase Transitions in Hydrazinium(2+) Sulfate
Authors: Okamoto Takeo , Nakamura Nobuo , Chihara Hideaki 
Published: July 2006

Abstract
The existence of a “diffuse” phase transition below room temperature has been confirmed in N2H6SO4 crystal by powder X-ray and DTA experiments. The transition temperature is very sensitive to the grain size. This size effect was discussed on the basis of the thermodynamic nucleation theory taking into account the interfacial energy between the high and the low temperature phases. The diffuse nature of the transition was interpreted by a theory proposed by Tobolsky et al. The spin-lattice relaxation times of 1H were redetermined and the nature of the cationic motion in each phase was discussed.
The Correlation of Basicity and Equilibrium Constants Evaluated from Lanthanoid-induced Shifts in the Eu(fod)3-p-Substituted Aniline Systems
Authors: Hirayama Masatoshi , Owada Masashiro 
Published: July 2006

Abstract
An approximate linear correlation has been found between the basicity of substrate (pKa) and the logarithm of the equilibrium constant K1 for 1:1 adducts evaluated from the least squares analysis of lanthanoid-induced shifts (LIS) for the systems containing Eu(fod)3 and a series of p-substituted anilines in CDCl3. In contrast, both the observed S-values and intrinsic shifts have shown no simple correlation to pKa’s of substrates.
Far-infrared Absorption of Non-dipolar Liquid Mixtures
Authors: Fujiwara Kenji , Ikawa Shun-ichi , Kimura Masao 
Published: July 2006

Abstract
Far-infrared absorptions of some non-dipolar liquid mixtures have been observed. The changes of the intensities with mixing ratio were examined on the basis of a formula derived for the difference between absorption intensities before and after mixing, to get information about the mixing state.
Kinetic Studies of the Proton-transfer of the Bivalent Anions of ortho-Hydroxy Azo Compounds in Dioxane–Water Media
Authors: Yoshida Noboru , Fujimoto Masatoshi 
Published: July 2006

Abstract
Kinetics of the proton-transfer reactions in dioxane-water media between hydroxide ion and the bivalent anions of 4-(2,4-dihydroxyphenylazo)benzenesulfonic acid (TPO) and 7-hydroxy-8-phenylazo-1,3-naphthalenedisulfonic acid (HPN) were studied by means of the temperature-jump method. For the change in the mole fraction of dioxane from 0 to 0.174, the acid-dissociation constant, Kac(s), was found to decrease from 1.07×10−11 to 5.25×10−14 mol dm−3 for HPN and from 1.32×10−12 to 7.08×10−15 mol dm−3 for TPO.
X-Ray Diffraction Studies on the Structures of Diammine- and Aquasilver(I) Complexes in Aqueous Solution
Authors: Maeda Masunobu , Maegawa Yoshiteru , Yamaguchi Toshio , Ohtaki Hitoshi 
Published: July 2006

Abstract
X-Ray diffraction studies were carried out for aqueous diamminesilver(I) nitrate, silver(I) perchlorate and nitrate solutions. The radial distribution curve of the diamminesilver(I) nitrate solution showed that the length of the Ag–NH3 bond is (2.22±0.02) Å. In the aqueous silver(I) perchlorate solution, a silver(I) ion is combined with two water molecules at a distance of (2.41±0.02) Å, the result being in good agreement with that obtained for the nitrate solution.
Enrichment of a Trace Amount of Manganese by the Mixed Resin Prepared from Finely Divided Anion and Cation Exchangers in the Presence of 4-(2-Pyridylazo)resorcinol
Authors: Abe Masutaro , Takei Noriko , Ohzeki Kunio , Kambara Tomihito 
Published: July 2006

Abstract
The enrichment of a trace amount of manganese(II) from sample water was carried out by the combined use of a mixture of finely divided cation and anion exchangers and 4-(2-pyridylazo)resorcinol (PAR). Manganese–PAR complex was effectively collected onto the mixed resin by batch method in the pH range 9.1–10.2. The manganese on the mixed resin was eluted into hydrochloric acid solution, extracted with 4-benzoyl-3-methyl-1 -phenyl-2-pyrazolin-5-one (BMPP) into MIBK and determined by atomic absorption spectrometry. The recovery of 3 μg of manganese from the synthetic sample solution (100–500 ml) was in the range 95–97%.
ortho-Disubstituted F-Benzenes. II. One-pot Syntheses of (F-Benzo)heterocyclic Compounds
Authors: Inukai Yoshinari , Sonoda Takaaki , Kobayashi Hiroshi 
Published: July 2006

Abstract
Convenient one-pot methods of converting F-benzene into substituted (F-benzo)furans, (F-benz)oxazole, -imidazolines, and -thiazoline are described. Ambident nucleophiles are generated in situ from ketone, amide, urea, thiourea, and their derivatives in the presence of sodium hydride. Enolate-anion nucleophiles are also generated in situ from silyl enol ethers in the presence of potassium fluoride in anhydrous DMF.
Induced Circular Dichroism of β-Cyclodextrin Complexes with Substituted Benzenes
Authors: Shimizu Hiroshi , Kaito Akira , Hatano Masahiro 
Published: July 2006

Abstract
The induced circular dichroism (ICD) of β-Cyclodextrin(β-CDx)-substituted benzene complexes was investigated. We observed the ICD on the absorption bands of achiral substituted benzene molecules, which is considered to be induced by the dissymmetric field of the chiral β-CDx host molecule. The electronic transitions which are polarized along the long axis of the substituted benzenes showed positive ICD, while the sings of the ICD of short-axis polarized transitions are negative. The rotational strengths of these inclusion complexes were calculated by the Kirkwood-Tinoco expression. From the comparison between the experimental and calculated results, it is concluded that these β-CDx complexes favor the axial inclusion in which the long axis of the substituted benzenes is parallel to the axis of the β-CDx cavity.
Simple and Practical Routes to 4,5-Benzocycloheptenone. Ring Enlargement of 3,4-Dihydro-2-ethoxynaphthalene and 2-Alkoxynaphthalenes with Dichlorocarbene
Authors: Uyehara Tadao , Ichida Akio , Funamizu Makoto , Nanbu Hirofumi , Kitahara Yoshio 
Published: July 2006

Abstract
An addition of dichlorocarbene generated by a phase-transfer reaction, to 3,4-dihydro-2-ethoxynaphthalene gave 7,7-dichloro-6-ethoxy-2,3-benzobicyclo[4.1.0]hept-2-ene, from which 4,5-benzocycloheptenone was derived in preparative yield. 2-Methoxy- and 2-ethoxynaphthalene were converted into 2-chloro-4,5-benzotropone in 33 and 66% yield, respectively, by treatment with large excess of ethyl trichloroacetate arid sodium methoxide.