bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Theory of the Adsorption Monolayer with Lateral Intermolecular Interaction and Its Application to Aqueous Alcohol Solutions
Authors: Nakagaki Masayuki , Yamamoto Mihoko 
Published: July 2006

Abstract
A theoretical relation between the fractional adsorption amount, θ, and the concentration, C, taking account of the lateral interaction between the adsorbed molecules is used to integrate the Gibbs equation, and the relation between the surface pressure, F, and the molecular area, A, is derived. Since the equation does not contain the parameter, k0, related to the strength of adsorption, it is concluded that there is no substantial difference between the adsorption monolayers and the insoluble monolayers. The relation between F and C is also derived and compared with the experimental data for normal alcohols. The standard affinity of adsorption, −Δμ0, and the energy of lateral interaction, ε, increased linearly with the number of carbon atoms of the alcohols, n. Finally, it has been shown that the experimental data can be explained well with the theoretical equation presented here, but not with Szyszkowski’s, the latter being derived for negligible lateral interaction.
Nickel(II) Complexes of N,N′-Polymethylenebis(o-mercaptobenzylamine)
Authors: Koyama Hiroyuki , Murase Ichiro 
Published: July 2006

Abstract
N,N′-Polymethylenebis(o-mercaptobenzylamine) ligands (polymethylene=ethylene 1,2-cyclohexylene, trimethylene, and tetramethylene) have been synthesized by the reduction of the corresponding amides, which were prepared by the condensation of 2,2′-dithiodibenzoyl chloride and polymethylenediamines, and then their nickel(II) complexes have been prepared and characterized. The elemental analyses and the magnetic and spectroscopic data indicate that all of the complexes are monomeric with metal-ligand ratio of 1: 1, and their geometries are essentially square-planar. When the bridging carbon chain was replaced from ethylene up to tetramethylene, the electronic spectra of the complexes exhibited pronounced change in the d-d bands.
Circular Dichroism Studies of a Series of (Ammine)[(RR)-2,4-pentanediamine]cobalt(III) Complexes
Authors: Kojima Masaaki , Fujita Miho , Fujita Junnosuke 
Published: July 2006

Abstract
The circular dichroism spectra of a series of complexes of the type [Co(NH3)2n(RR-ptn)3−n]3+(n=0, 1,2), where the RR-ptn is (RR)-2,4-pentanediamine, were recorded in aqueous solutions with and without the addition of electrolytes such as chloride or sulfate, and in DMSO solutions. The circular dichroism spectra in the region of the first absorption band of Δ-[Co(RR-ptn)3]3+ and cis-Δ-[Co(NH3)2(RR-ptn)2]3+ were extremely sensitive to the environment of the complexes and showed a remarkable variation, while those of the corresponding diastereomers, Λ-[Co(RR-ptn)3]3+ and cis-Λ-[Co(NH3)2(RR-ptn)2]3+ were little affected by the given environment. The other complexes, trans-[Co(NH3)2(RR-ptn)2]3+ and [Co(NH3)4(RR-ptn)]3+ exhibited small variations in the circular dichroism spectra. These variations seem to be accounted for by the conformational change of the flexible sixmembered chelate ring brought about by ion-pair formation between the complex cations and anions.
Mechanism of Photochemical Reaction of Friedelin with Diethyl Ether and with Acetone
Authors: Shirasaki Hidekazu , Tsuyuki Takahiko , Takahashi Takeyoshi , Stevenson Robert 
Published: July 2006

Abstract
Photo-irradiation of friedelin (1) in diethyl ether gave a keto ether (2), a hydroxy ether (3), and an alcohol (4). A hydroxy ketone (5) was formed by the photo-irradiation reaction of 1 in diethyl ether containing acetone. In the latter case, labeled experiments showed that the photo-produced ketene (12) reacted with 1-hydroxy-1-methylethyl radical derived from acetone to give 5. The formation of 2 could be explained by an attack of an α-radical derived from diethyl ether to 12. Both 3 and 4 were shown to be derived from a norseco-aldehyde (11) which was produced from the ketene (12).
A New Method for the Synthesis of 1-Cycloalkenyl Alkyl Sulfides
Authors: Akiyama Fuminori 
Published: July 2006

Abstract
2-Isopropyl-5-methyl-1-cyclohexenyl alkyl sulfides were obtained in about a 60% yield by the reaction of 2-isopropyl-5-methylcyclohexanone with thioacetals or thiols in the presence of aluminum chloride. 1-Cycloalkenyl ethyl sulfides, (Remark: Graphics omitted.) (n=4, 5, or 6, R=H or alkyl) were obtained in good yields by the reaction of cycloalkanones with ethanethiol in the presence of diphosphorus pentaoxide. However, an attempt to apply this method to acyclic vinyl sulfides was unsuccessful.
Synthesis of Optically Active Bis(1-mesitylethyl) Ethers
Authors: Nakatani Munehiro , Kamikawa Tadao , Hase Tsunao , Kubota Takashi 
Published: July 2006

Abstract
The racemic and meso bis(1-mesitylethyl) ethers were synthesized. The optical resolution of the dicarboxylic acid derivative showed that the high-melting compounds were racemic in form and the low-melting isomers meso in form.
Amidrazones and Related Compounds. V. The Formation of Pyrazole, 1H-1,2,4-Triazepine, and 4H,11H-[1,5]Diazocino-[2,3-e: 6,7-e′]di[1H-1,2,4]triazepine Derivatives
Authors: Takahashi Masahiko , Sugawara Noriyuki , Yoshimura Kaoru 
Published: July 2006

Abstract
Amidrazones RC(NH2)=NNH2 (1a, b) (R=2-pyridyl, phenyl) reacted with EtOCH=CR1R2 (2a–d) (R1R2=CN, CO2C2H5, COCO2C2H5) to give RC(NH2)=NNHCH=CR1R2 (3a–g). 3,4-Disubstituted pyrazoles (4a, b) were obtained on the heating of 3a, b, e, and f (R=2-pyridyl, phenyl, R1=CN, R2=CN, CO2C2H5) in toluene. However, the heating of 3c (R=2-pyridyl, R1=R2=CO2C2H5) gave a dimer, the 2,3,7,9,10-pentaazadodeca-1,4,8,11-tetraene derivative (9), instead of 4. 5-Amino-6-ethoxycarbonyl-3-(2-pyridyl)-1H-1,2,4-triazepine (10) was obtained by the reaction of 3a (R=2-pyridyl, R1=CN, R2=CO2C2H5) with ethanolic hydrogen chloride. The treatment of 10 with alkaline gave 2,9-di-2-pyridyl-6,7,13,14-tetrahydro-4H,11H-[1,5]diazocino-[2,3-e:6,7-e′]di[1H-1,2,4]triazepine-6,13-dione (11). Triazepine (10) reacted with hydrazines to give 5-hydrazino-1H-1,2,4-triazepine derivatives (13a, b).
Synthesis of a Masked Derivative of 3′-Deoxydihydrostreptobiosamine, a Precursor for the Synthesis of 3″-Deoxydihydrostreptomycin
Authors: Sano Hiroshi , Tsuchiya Tsutomu , Kobayashi Shigeru , Umezawa Hamao , Umezawa Sumio 
Published: July 2006

Abstract
2′-N-Acetyl-4′,6′-di-O-acetyl-3,3a-O-carbonyl-3′-deoxydihydrostreptobiosamine (15), a precursor in the synthesis of 3″-deoxydihydrostreptomycin, was prepared from benzyl α-dihydrostreptobiosaminide. The synthesis involves formation of l-allo compound (5) with inversion of the 3′-hydroxyl group of l-gluco derivative (2) in order to facilitate 3′-chlorination, dechlorination, of the 3′-chloro-l-gluco derivative (7 or 11) with tributyltin hydride, and utilization of cyclic 3,3a-O-carbonyl group instead of 3,3a-O-isopropylidene group which was unstable in the later reactions.
A Semi-empirical Calculation of the Substituent Effects on the 1H Chemical Shifts of 1-Substituted Naphthalenes
Authors: Niwa Jun 
Published: July 2006

Abstract
A semi-empirical equation for predicting the 1H chemical shift induced by substituents in an aromatic system (J. Niwa, Bull. Chem. Soc. Jpn., 48, 118, 1637 (1975)) has been applied to the ring protons of 1-substituted naphthalenes. The predictions of the equation are tested against the available experimental data for six representative substituents and are also compared with those of the electric-field model.
Effects of Pressure on the Disproportionation of Olefins over MoO3–Al2O3 and Re2O7–Al2O3 Catalysts
Authors: Sodesawa Toshiaki , Ogata Eisuke , Kamiya Yoshio 
Published: July 2006

Abstract
The disproportionation of propylene and 1-butene over MoO3–Al2O3 and Re2O7–Al2O3 catalysts was carried out in order to investigate the effects of reaction pressure in the range from 1.0 to 130 kg/cm2. The effects of the pressure on the reaction can be identified as two independent of the reaction phase; the catalytic activity increased with the reaction pressure, and the time needed to reach the maximum conversion (Tmax) as well as the time when the conversion falls to half the maximum value (τ1⁄2) decreased with the increase in the reaction pressure. It can be concluded that the catalytic activity by the polymers formed over the catalyst falls off rapidly with the increase in the pressure. In both phases, the disproportionation of olefins over the Re2O7–Al2O3 catalyst exhibits the following features as compared with that over the MoO3–Al2O3 catalyst: (1) a much higher activity at temperatures of 0–140 °C; (2) a much higher selectivity for disproportionation, and (3) a lower apparent activation energy.
Radiation Chemical Reactions in Carbon Dioxide–Propane System. III. Formation of Oxygen Containing Products
Authors: Ikezoe Yasumasa , Sato Shoichi 
Published: July 2006

Abstract
The G value of water and 2-propanol as well as that of carbon monoxide decreased with decrease in propane concentration below 0.5%, the value of acetone remaining constant. Considering the effects of dose rate and irradiation temperature on the product yields, the results indicate that the formation of water and 2-propanol competes with the back reaction, or the reoxidation of carbon monoxide. A clustered negative ion, O−(CO2)n seems to be the oxidizing species responsible both for the back reaction and the formation of water and 2-propanol. The G value of O−(CO2)n was estimated to be 1.3. The formation of acetone is independent of the back reaction.
Viscoelastic Behavior of Some Di(normal alkyl) Phthalates
Authors: Kinjo Noriyuki , Nakagawa Tsurutaro 
Published: July 2006

Abstract
The viscoelastic behavior of a homologous series of di-n-alkyl phthalates varying in alkyl chain length from methyl- to nonyl- was studied by means of torsional braid analysis (TBA). The glass transition temperatures, Tg were determined as the temperature at loss maximum. The Tg decreases with increasing alkyl chain length in the di-n-alkyl phthalates, up to dibutyl. Thereafter, the Tg increases gradually with further increase in the alkyl chain length. This behavior can be explained by taking into account two factors which determine the Tg, the molecular weight and the intermolecular interaction. The increase in the number of methylene groups in the phthalates brings about two effects: first, the Tg is increased with increasing molecular weight and, second, the Tg is decreased owing to shielding of the interaction between polar carbonyl groups due to the presence of non-polar methylene groups. When the number of methylene groups is four, the two effects counterbalance each other and the Tg of dibutyl phthalate is the lowest of the di-n-alkyl phthalate series.
Absorption Spectra of Inter- and Intramolecular Exciplex Systems of Pyrene and N,N-Dimethylaniline in Alcoholic Solutions
Authors: Hinatu Junji , Masuhara Hiroshi , Mataga Noboru , Sakata Yoshiteru , Misumi Soichi 
Published: July 2006

Abstract
Absorption spectra of inter- and intramolecular exciplex systems of pyrene and N,N-dimethylaniline in alcoholic solution were obtained by means of ns laser photolysis. The spectra of intermolecular systems can be reproduced by the superposition of bands of the pyrene anion and the N,N-dimethylaniline cation. Similar results were obtained with intramolecular systems of P1 and P2, where Pn is (1-pyrenyl)-(CH2)n-(p-dimethylaminophenyl). The absorption band of P3 exciplex is structureless and very broad, the position of the maximum remaining unchanged. From the relation between absorption spectra and conformation of intramolecular systems, it is concluded that the broad band is due to the sandwich type of structure of the donor cation and the acceptor anion. Anomalous behavior of intermolecular exciplexes in alcoholic solutions is discussed on the basis of their absorption spectra.
Kinetics of Oxidation of 4-Hydroxy-4-methyl-2-pehtanone by Sodium N-Chloro-p-toluenesulfonamide
Authors: Uma K V , Mayanna S M 
Published: July 2006

Abstract
The kinetics of oxidation of 4-hydroxy-4-methyl-2-pentanone (diacetone alcohol) by sodium N-chloro-p-toluenesulfonamide (Chloramine-T, RNClNa) in presence of hydrochloric acid (0.05–0.6 M) has been studied at 30 °C. The reaction follows first order kinetics with respect to chloramine-T. The reaction rate depends on the square of the [H+] and independent of the alcohol concentration. The energy and entropy of activation have been found to be 65.56 kJ mol−1 and −73.81 JK−1 respectively. The rate of reaction has been affected by the addition of potassium chloride and dioxane to the reaction mixture. A mechanism has been proposed involving diacetone alcohol and H2OCl+ formed by the hydrolysis of chloramine-T. Applying steady state condition to RNHCl, a rate expression has been given to account for the observed results. Kinetic data have been used in the analytical estimation of diacetone alcohol in acidic medium.
Japanese Tea Leaves: A Possible Biological Standard Reference Material
Authors: Fuwa Keiichiro , Notsu Kenji , Tsunoda Kin-ichi , Kato Hideaki , Yamamoto Yuko , Okamoto Kensaku , Dokiya Yukiko , Toda Shozo 
Published: July 2006

Abstract
Japanese Tea Leaves, prepared by pulverizing with an agate ball mill and sieving with a Saran fiber sieve (50 mesh) were assessed as a possible biological standard reference material for elemental analysis. The metal content of the tea leaves was determined independently at two laboratories using atomic absorption and flame emission spectrometry. Neutron activation analysis was also performed to determine the content (21 elements) of Tea Leaves. For some elements the result from the various methods were compared. The characteristics of Tea Leaves are discussed and the elemental composition is compared to that of Orchard Leaves (NBS SRM, 1571). The most significant characteristic of Tea Leaves was the high manganese content.
Trimethylenediamine Complexes. IV. Kinetics and Mechanism of Acid and Base Hydrolysis of Tetranitro(ethylenediamine)- and Tetranitro(trimethylenediamine)cobaltates(III)
Authors: Ito Yoshiaki , Kawaguchi Shinichi 
Published: July 2006

Abstract
Hydrolysis of Co(NO2)4(AA)− (AA=en or tn) was studied in acidic and basic aqueous solutions by the spectrophotometric method. In faintly acidic solution (6&gt;pH&gt;4) the aquation proceeds reversibly to attain an equilibrium with Co(NO2)3(H2O) (AA), Keq being (1.71±0.03)×10−2 and (3.55±0.06)×10−2 mol·1−1 for AA=en and tn, respectively, at 25.0 °C and μ=0.1. With increasing concentration of hydrogen ion the acid-catalyzed pathway becomes increasingly important. In basic solution (12.2&gt;pH&gt;9.5) Co(NO2)3(OH)(AA)− was formed irreversibly as the first product. Kinetic data of these hydrolysis reactions are interpreted in terms of the dissociative mechanism involving a five-coordinate intermediate Co(NO2)3(AA). The rates of nitrite release from Co(NO2)4(tn)− ((9.27±0.03)×10−4s−1) and deaquation from Co(NO2)3(H2O)(tn) ((3.95±0.12)×10−4 s−1) are several times greater than those for the corresponding ethylenediamine complexes ((2.08±0.01)×10−4 and (5.46±0.10)×10−5 s−1, respectively.
The Stereochemistry of 3-Hydroxy-2-methylbutyric Acid
Authors: Tai Akira , Imaida Motomasa 
Published: July 2006

Abstract
Four stereoisomers of methyl 3-hydroxy-2-methylbutyrate (I), (+)-threo-I, (−)-threo-I, (+)-erythro-I, and (−)-rythro-I, were prepared, and their absolute configurations were determined. The configurations of (+)-threo-I, [α]D20+36.80° (c 5, methanol) and (+)-erythro-I, [α]D20+14.32° (c, 5, methanol) were assigned to (2S, 3S) and (2S, 3R) respectively.
Structural Studies of the Interaction between Indole Derivatives and Biologically Important Aromatic Compounds. I. The Crystal and Molecular Structure of the Indole-3-acetic Acid-Nicotinamide (1:1) Complex
Authors: Inoue Masatoshi , Sakaki Toshimasa , Fujiwara Takaji , Tomita Ken-ichi 
Published: July 2006

Abstract
The title complex crystallizes in the monoclinic space group P21/c. The unit-cell dimensions are a=11.287(5), b=5.110(3), c=26.391(3) Å, and β=107.07(2)°. The crystal structure was solved by a direct method. By block-diagonal least-squares refinements, the R-value dropped to 0.069. All the nitrogen and oxygen atoms in the complex participate in the hydrogen bonding. No prominent overlapping between pyridine and indole rings is observed in the crystal. Both molecules are hydrogen-bonded to form infinite-layered structures perpendicular to the c-axis; those structures are held together by van der Waals contacts.
Oxidative Degradation of Polymers. V. Ozonization of Polypropylene and Polystyrene in Carbon Tetrachloride
Authors: Saito Tsuneo , Niki Etsuo , Shiono Takeo , Kamiya Yoshio 
Published: July 2006

Abstract
The rates and products of ozonization of atactic polypropylene and polystyrene were studied in carbon tetrachloride at 30 and 70 °C. Atactic polypropylene underwent cleavage statistically by ozone to give oxygenated products. The molecular weight of polypropylene decreased with the progress of ozonization. Most chain ends of ozonized polypropylene were suggested to be carboxylic acids. Ozonization of polystyrene brought about crosslinking as well as chain scission, giving rise to broadening of molecular weight distribution. The major product from polystyrene was carboxylic acid.
Gel Chromatography of β-Diketones and Their Metal Complexes. IV. The Partition Concept in Gel Chromatography
Authors: Saitoh Koichi , Suzuki Nobuo 
Published: July 2006

Abstract
A new theoretical treatment of the solute distribution in gel chromatography is proposed. Practical gel chromatography can be regarded as one based on a combined function of the molecular sieve effect and the partition effect. Introducing the concept of a regular solution to the column system of gel chromatography, the contribution of the partition effect can be estimated from the data on the physical properties of the solute, the solvent, and the gel matrix. The argument being proposed is supported by the experimental data on the gel chromatography of metal (II, III) chelates with acetylacetone and normal alkanes previously obtained in the systems of a poly(vinyl acetate) gel and various eluting solvents.
The Relative Rates of Ene Reaction of Benzyne with Cyclic Olefins: The Stereochemical Course
Authors: Kato Masahiko , Okamoto Yukio , Chikamoto Takeji , Miwa Toshio 
Published: July 2006

Abstract
The benzyne reaction of cyclic olefins, in competition with that of cyclohexene has been studied. The relative reactivities for ene reaction and the stereoselectivity of the reaction with 4-t-butylcyclohexene, which afforded trans-5-t-butyl-3-phenylcyclohexene and cis-3-t-butyl-6-phenylcyclohexene, are consistent with the stereochemical requirements along the reaction pathway.
Reactions of Tetramethylbenzenedicarbonitriles and Tetramethylbenzonitriles with Fuming Nitric Acid. A New Route to Some Substituted Phthalides and 1,3-Dihydroisobenzofuran-1-imines
Authors: Suzuki Hitomi , Koge Mamie , Inoue Akiyoshi , Hanafusa Terukiyo 
Published: July 2006

Abstract
The reaction of tetramethylbenzenedicarbonitriles and tetramethylbenzonitriles with fuming nitric acid (d=1.5) has been investigated at room temperature in the dark. 2,4,5,6-Tetramethylbenzene-1,3-dicarbonitrile and 2,3,5,6-tetramethylbenzene-1,4-dicarbonitrile gave, after aqueous work-up, 4-cyano-5,6,7-trimethyl- and 5-cyano-4,6,7-trimethylphthalides, respectively, in high yields, while 3,4,5,6-tetramethylbenzene-1,2-dicarbo-nitrile produced appreciable amounts of two cyanonitro-3-cyclohexen-1-ones in addition to 7-cyano-4,5,6-trimethylphthalide. Similarly, 2,3,4,6- and 2,3,5,6-tetramethylbenzonitriles afforded 4-nitro-5,6,7-trimethyl- and 5-nitro-4,6,7-trimethylphthalides, respectively, along with the expected nitro compounds. In contrast, 2,3,4,5-tetramethylbenzonitrile underwent normal nitration, giving 6-nitro derivative as the sole product. The phthalide formation was found to proceed through 1,3-dihydroisobenzofuran-1-imines presumably derived from the initially formed o-cyanobenzyl nitrates. The reaction appears to provide potential utility in the synthesis of some substituted phthalides and 1,3-dihydroisobenzofuran-1-imines.
Asymmetric Reactions. III. The Asymmetric Synthesis of Methyl 2-Phenylpropionate in the Presence of Chiral Polymers
Authors: Yamashita Tetsushi , Yasueda Hiroshi , Nakatani Noriyuki , Nakamura Nobuo 
Published: July 2006

Abstract
The asymmetric addition of methanol to phenylmethylketene was carried out in the presence of a chiral polymer obtained by the co-polymerization of N-benzyl-2-pyrrolidinylmethyl acrylate with methyl acrylate. The products obtained for the above co-polymer showed a correlation between logkR⁄kS and 1⁄T deviating from linearity, while those for poly(N-benzyl-2-pyrroIidinylmethyl acrylate) exhibited a linear relationship. N-Benzyl-2-pyrrolidinylmethyl butyrate, hexanoate, and stearate were also used as catalysts; they showed asymmetric efficiencies intermediate between those of N-benzyl-2-pyrrolidinylmethyl propionate and poly(N-benzyl-2-pyrrolidinylmethyl acrylate). The use of several high- and low-molecular-weight catalysts derived from cinchonine was similarly attempted in order to examine the polymer effect with regard to the stereoselectivity.
The Effect of Macrocyclic Polyethers on the Alkylation of Sodium 2-Naphtholate
Authors: Akabori Sadatoshi , Tuji Hiroyuki 
Published: July 2006

Abstract
The alkylation of sodium 2-naphtholate, in the presence of benzo-18-crown-6 or 4,7,13,16,21,24-hexaoxabicyclo[8.8.8]hexacosane is found to give high ratios of O/O+C alkylation when conducted in THF, in benzene, and in water. The striking increase in the product ratio is attributed to a specific complexation of the macrocyclic polyethers, which facilitate the dissociation of the ion-pair aggregate of the sodio-derivative which exists in benzene or THF. The polyethers may act as phase-transfer catalysts when the reaction is run in water. In support of this conclusion, the reaction in DMF or acetonitrile, in which the dissociation of sodium 2-naphtholate takes place, fails to show any effect of the macrocyclic polyethers on the product ratio.
Photolyses of S,S-Dimethyl-N-(ethoxycarbonyl)sulfimide in Hydrocarbons and in Oxygen Compounds
Authors: Torimoto Noboru , Shingaki Tadao , Nagai Toshikazu 
Published: July 2006

Abstract
The behavior of ethoxycarbonylnitrene (3), generated photochemically from S,S-dimethyl-N-(ethoxycarbonyl)sulfimide (1), upon insertion into the C–H bonds and the O–H bonds was compared with that of 3 generated from ethyl azidoformate (2). Ethoxycarbonylnitrene generated from 1 was inserted preferentially into the α C–H bonds of cyclic ethers. The relative reactivity toward 3 of the primary, secondary, and tertiary C–H bonds in 2,4-dimethylpentane is in the ratio of 1 : 9 : 35. The insertion of 3 into the tertiary C–H bonds of cis- and trans-1,4-dimethylcyclohexanes proceeded stereospecifically. The reaction of 3 with alcohols gave the O–H insertion products. These results show that the insertion of 3 generated from 1, as well as that of the nitrene from 2, into the hydrocarbon C–H bo nds and the O–H bonds proceeds only for the singlet.
Synthesis of 2,3 : 7,8-Bis(polymethylene)-4H,9H-benzo[1,2-b : 4,5-b′]dipyrans and Their Oxidation to the Corresponding Benzodilactones
Authors: Mahajan Jaswant Rai , Monteiro Maria Beatriz 
Published: July 2006

Abstract
Four members of a new series of the title benzodipyrans have been synthesized through the alkylation of the pyrolidine-enamines of 6,7,8- and 12-membered cycloalkanones with 2,5-bis(dimethylaminomethyl)hydroquinone, followed by hydrolysis and subsequent cyclization of the intermediate products. Oxidation of these benzodipyrans with m-chloroperbenzoic acid (MCPBA) afforded the corresponding benzodilactones in 10–65% yield, the rest of the material being a mixture of hydroxylated carbonyl compounds.