bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on 2-Aziridinecarboxylic Acid. IV. Total Synthesis of Actinomycin D (C1) via Ring-opening Reaction of Aziridine
Authors: Tanaka Takumi , Nakajima Kiichiro , Okawa Kenji 
Published: July 2006

Abstract
Actinomycin D (C1) has been synthesized by a route involving the ester formation between two peptide fragments, (2S,3S)-1-(2-nitro-3-benzyloxy-4-methylbenzoyl)-3-methyl-2-aziridinecarbonyl-d-valylproline t-butyl ester and N-benzyloxycarbonylsarcosyl-N-methylvaline, via a ring-opening reaction of aziridine. Cyclization, followed by reduction and oxidation, gave actinomycin D (C1). The synthetic actinomycin D (C1) was indistinguishable from natural substance as regards physical properties and biological activity.
Synthesis of Methyl 2,6-Di-N-acetyl-2,3,4,6,7-pentadeoxy-l-lyxo-heptopyranoside, a Derivative of 6-epi-d-Purpurosamine B
Authors: Suami Tetsuo , Honda Yutaka , Kato Tsuguhiro , Masu Mikio , Matsuzawa Kinya 
Published: July 2006

Abstract
6-epi-d-Purpurosamine B, 2,6-diamino-2,3,4,6,7-pentadeoxy-l-lyxo-heptopyranose, was found to be a component of antibiotic fortimicins. Methyl 2,6-di-N-acetyl-6-epi-α-d-purpurosaminide B has been synthesized from methyl 2-acetamido-2-deoxy-6-O-trityl-α-d-glucopyranoside.
The Structure of Nitronitrosoaconitinic Acid, the Oxidation Product of Aconitine with Nitric Acid
Authors: Amiya Takashi , Kanaiwa Yoshio , Bando Hideo , Nakano Naomi , Mori Takao , Suginome Harusada 
Published: July 2006

Abstract
The structure of nitronitrosoaconitinic acid, which is an oxidation product of aconitine with nitric acid, was confirmed by spectroscopic methods. This compound is a new type of acid, a 2-nitro-2-cyclohexen-1-one, with a pKa value comparable to that of carboxylic acids.
Kinetic Studies on the Decomposition of the Most Typical Meisenheimer Complex of Sodium 1,1-Dimethoxy-2,4,6-trinitrocyclohexadienide in Methanol
Authors: Abe Takehiro 
Published: July 2006

Abstract
The whole decomposition of the Meisenheimer complex formed from 2,4,6-trinitroanisole (TNA) and sodium methoxide proceeds in three steps and obeys the first-order kinetics in each step. The rate of the whole decrease of concentration of the complex is given by −d([TNA·CH3ONa]+[TNA·CH3O−])/dt=(k1[H+]+k2[CH3OH])×[TNA·CH3ONa]+(k3[H+]+k4[CH3OH])×[TNA·CH3O−]−k5[CH3O−]×[TNA], where k denotes a rate constant. This leads to the modification of the conventional unimolecular mechanism shown by TNA·CH3O−→TNA+CH3O−.
Oxidation of Methyl (Methylthio)methyl Sulfoxide
Authors: Ogura Katsuyuki , Suzuki Michiyo , Tsuchihashi Gen-ichi 
Published: July 2006

Abstract
Oxidation of methyl (methylthio)methyl sulfoxide (2) with hydrogen peroxide in acetic acid or methanol produced bis(methylsulfinyl)methane in high yield. Similar results were obtained in oxidation of 2 with ozone, sodium metaperiodate, and m-chloroperbenzoic acid. In contrast, methyl (methylthio)methyl sulfone (4) was exclusively formed when oxidation of 2 with hydrogen peroxide was carried out in methanol in the presence of sodium hydroxide. Furthermore, we established a convenient and efficient method of preparing 4 by oxidation of 2 with potassium permanganate.
Photochemical Type I and II Elimination Reactions of Dialkyl (Trichloromethyl)phosphonates
Authors: Suzuki Nobutaka , Kawai Teruyuki , Inoue Susumu , Sano Naoki , Izawa Yasuji 
Published: July 2006

Abstract
Irradiation of diisobutyl, dipropyl, and diethyl (trichloromethyl)phosphonates in MeCN gave corresponding monoesters and olefins via photochemical type II elimination. In addition, products via type I elimination were obtained from diisobutyl (trichloromethyl)phosphonate and its dimethyl ester.
On the Thermal Decomposition of Shock-heated SO2
Authors: Saito Ko , Yokubo Teiji , Higashihara Tetsuo , Murakami Ichiro 
Published: July 2006

Abstract
The SO2 pyrolysis was measured behind reflected shock waves under low SO2 concentrations. A typical induction zone was observed in the decomposition process. It was found that the overall rate constants after the induction zone were in good agreement with the values for the primary reaction obtained by the following investigators: Just and Rimpel, Kiefer, and Grillo et al. This implies that, even in highly diluted mixtures at low pressures, the kinetics of the SO2 decomposition is complicated.
Nitrogen 14 Nuclear Qnadrupole Resonance of Alloxan·H2O
Authors: Maruizumi Takuya , Hiyama Yukio , Niki Eiji 
Published: July 2006

Abstract
The 14N nuclear quadrupole resonance spectra of alloxan·H2O have been observed at room temperature. The predominant tautomer in a solid is concluded to be 5,5-dihydroxypyrimidine-2,4,6-trione. The NQR data were interpreted qualitatively by means of the Townes and Dailey theory.
Ground-state Energy Stabilization in Solid Cation Radical Salts Derived from Some Aromatic Hydrocarbons
Authors: Iida Yôichi 
Published: July 2006

Abstract
The ground-state energy stabilization due to the charge-transfer interaction between cation radicals was examined with solid cation radical salts of 9,10-dimethylanthracene, 9,10-dichloroanthracene, and perylene with antimony pentachloride and perchlorate anions.
An X-Ray Photoelectron Spectroscopic Study of Several Metal Complexes of 2-Mercaptobenzimidazole and 2-Mercaptobenzoxazole
Authors: Yoshida Tooru 
Published: July 2006

Abstract
The X-ray photoelectron spectra of several metal complexes of 2-mercaptobenzimidazole and 2-mercaptobenzoxazole were measured in order to examine the mode of coordination of the ligands. From their N(1s) and S(2p3⁄2) chemical shifts, it was suggested that the ligands are coordinated through both the sulfur and nitrogen atoms in most of the complexes.
The Liquid-Liquid Extraction of Zinc with Polyethylene Glycol and Poly(oxyethylene)-type Nonionic Surfactants
Authors: Suzuki Toshio , Murakami Naoyuki , Sotobayashi Takeshi 
Published: July 2006

Abstract
The Zn(II) extraction was made from its acidic thiocyanate solution, using polyethylene glycol and its mono(alkylphenyl) ether as extractants. The effects of the number of oxyethylene groups (–O–CH2–CH2–) per molecule and of the kind of the counter cation of thiocyanate on the extractability are described, together with some other factors affecting the Zn(II) extraction.
Solid State Reactions between Rare Earth Orthophosphate and Oxide
Authors: Hikichi Yasuo , Hukuo Ken-iti , Shiokawa Jiro 
Published: July 2006

Abstract
Solid state reactions between rare earth orthophosphate (RPO4) and oxides (SiO2, Al2O3, or CaO) in the air were studied by means of X-ray diffractometry. RPO4 does not react with SiO2, decomposing on heating above 1800 °C with Al2O3, or above 700 °C with CaO.
The Chemistry of 1,3-Glycol Derivatives. III. The Preparation of 1,1-Bis(1-hydroxyalkyl)cyclopropanes and Their Halogenation
Authors: Itoh Osamu , Kohmura Yoshiro , Ichikawa Yasunori , Umezu Makoto , Okita Tsutomu , Ichikawa Katsuhiko 
Published: July 2006

Abstract
By the reduction of 1,1-diacylcyclopropanes and their related compounds, several kinds of 1,1-bis(1-hydroxyalkyl)cyclopropanes have been prepared. Some of the stereoisomers were separated, and their configurations were determined by the NMR study of the 1,3-dioxanes prepared by the acetallization of the diols. The diols were subjected to halogenation. Although the reactions of meso- and dl-bis(1-hydroxyethyl)cyclopropanes with thionyl chloride and phosphorus pentachloride gave normal dichlorides, accompanied by slight skeletal rearrangements, the stereospecificities were rather low. With ZnCl2–HCl, the specificities were lost completely and large amounts of the homoallyl derivative were formed. The reaction mechanism is discussed.
The Reactions of Copper(I) 1-Alkenyltrimethylborates with Allylic Bromides or 2-Propynyl Bromide
Authors: Miyaura Norio , Yano Takashi , Suzuki Akira 
Published: July 2006

Abstract
The reactions between copper(I) 1-alkenyltrimethylborates (readily obtainable from 2-(1-alkenyl)-1,3,2-benzodioxaboroles and methyllithium) and allylic bromides or 2-propynyl bromide were found to give corresponding coupling products. These reactions provide new synthetic routes to 1,4-alkadienes or 1,2,7-alkatrien-5-ynes.
The Removal of Arsenate in Waste Water with an Adsorbent Prepared by Binding Hydrous Iron(III) Oxide with Polyacrylamide
Authors: Shigetomi Yasumasa , Hori Y\={o}ichi , Kojima Takehiro 
Published: July 2006

Abstract
Studies have been made to remove arsenate in waste water with an adsorbent prepared by binding hydrous iron(III) oxide with polyacrylamide. Arsenate anions were thus adsorbed over the pH range of 5–8; the adsorption capacity of arsenate was 43 mg per gram of the adsorbent.
The Dissociation Rate of S2 Produced from COS Pyrolysis
Authors: Higashihara Tetsuo , Saito Ko , Murakami Ichiro 
Published: July 2006

Abstract
The disappearance rate of S2, which was produced from the pyrolysis of COS, was measured behind incident shock waves by monitoring the UV emission in the temperature range of 4500–6000 K and in the pressure range of 0.32–0.5 atm. It was found that two processes could possibly account for the disappearance of S2:
S_2+Ar→2S+Ar\ ag3
and
(Remark: Graphics omitted.)
and the following rate equation was obtained:
-d[S_2]/dt=k_II[S_2][Ar]mol cm^-3s^-1
where
k_II=10^13.68exp(-77kcal/RT)cm^3mol^-1s^-1.
Structural Studies of Fortimicins. II. Crystal and Molecular Structure of Fortamine
Authors: Hirayama Noriaki , Shirahata Kunikatsu , Ohashi Yuji , Sasada Yoshio 
Published: July 2006

Abstract
Fortamine, l-3-amino-1-methoxy-6-methylamino-1,3,6-trideoxy-chiro-inositol, is a component of fortimicins which are potent aminocyclitol antibiotics. The space group is P21 with a=9.454(1), b=6.6957(8), c=7.622(1) Å, β=95.93(2)°, and two C8H18N2O4’s per unit cell. The structure was solved by direct methods, least-squares refinement using 932 reflexions giving the final R value of 0.033. The ring conformation of fortamine is closer to the ideal chair form than that of the fortamine moiety in fortimicin B. The strain caused by the intramolecular hydrogen bond and glycosidic bond in fortimicin B is released in fortamine.
Dissociation of μ-Oxo-bis[oxobis(8-quinolinolato)vanadium(V)] and μ-Oxo-bis[oxobis(4-isopropyltropolonato)vanadium(V)] in Chlorobenzene
Authors: Yuchi Akio , Muranaka Hiroshi , Yamada Shinkichi , Tanaka Motoharu 
Published: July 2006

Abstract
Dissociation of dimeric vanadium(V) complexes with 8-quinolinol(Hox) and 4-isopropyltropolone(Hipt), V2O3(ox)4 and V2O3(ipt)4, in organic solvents was studied spectrophotometrically. The equilibrium is found to be
V_2O_3L_4+H_2O\ightleftarrows2VO_2L+2HL
with the following logarithmic equilibrium constants: logK=−12.9 for L=ox− and −12.8 for L=ipt− in chlorobenzene. VO2L was synthesized and characterized by IR, UV, and visible spectroscopy for these ligands and also for 2-methyl-8-quinolinol.
Equilibrium, X-Ray, and 1H-NMR Studies of the ZrCr2–H System
Authors: Imoto Hideo , Sasaki Motoshige , Saito Taro , Sasaki Yukiyoshi 
Published: July 2006

Abstract
The pressure isotherms of the ZrCr2–H system (20–200 °C, 10–700 Torr) and powder X-ray diffraction have shown the occurrence of two phases, cubic ZrCr2Hx (x&lt;1.0) and hexagonal ZrCr2Hx (2.5&lt;x&lt;3.5). From the gradual change in the diffraction pattern with x, it has been concluded that samples with a low hydrogen concentration (x&lt;0.8) contain another hexagonal phase. All these phases have Laves-type structures (C14 and C15). At 106 K, ZrCr2H2.66 has a much smaller second moment (7.2 G) of 1H-NMR than the value calculated from the random-distribution model (77.9 G), which shows that the nearest sites can not be filled by hydrogen atoms at the same time. The system of TiCr2–H has also been studied for comparison.
Circular Dichroism and Stereochemistry of Tetranuclear Cobalt(III) Complexes of Hexol Type. III. The meso-2,3-Butanediamine, (R)-1,2-Propanediamine, and (R,R)-1,2-Cyclohexanediamine Complexes
Authors: Kudo Tomikatsu , Shimura Yoichi 
Published: July 2006

Abstract
Eight, six, and four optical isomers of diamine hexols [Co{(OH)2Co(diarnine)2}3]6+ containing meso-2,3-butanediamine, (R)-1,2-propanediamine, and (R,R)-1,2-cyclohexanediamine, respectively, were separated by column chromatography. The absorption and CD (circular dichroism) spectra were measured in the visible and ultraviolet regions in 0.01 mol dm−3 HCl, the absolute configurations being determined mainly on the basis of the CD spectra. Assuming that the configurational chiralities are identical to those of the corresponding ethylene-diamine hexol isomers, it has been established that the lel and ob orientations of the (R)-diamine ligand show different vicinal CD curves due to the asymmetric carbon atom in the ligand.
Synthesis of (±)-Dihydrofomannosin Acetate
Authors: Kosugi Hiroshi , Uda Hisashi 
Published: July 2006

Abstract
The synthesis of (±)-dihydrofomannosin acetate [5-acetoxymethyl-1-(4,4-dimethyl-2-oxocyclopentyl)-3-oxabicyclo[4.2.0]oct-5-en-4-one] is described. Photocycloaddition of 4-(2-acetoxy-4,4-dimethylcyclopentyl)-2(5H)-furanone to ethylene gave 5-(2-acetoxy-4,4-dimethylcyclopentyl)-3-oxabicyclo[3.2.0]heptan-2-one, which was converted into ethyl [2-acetoxymethyl-2-(2-acetoxy-4,4-dimethylcyclopentyl)cyclobutyl]glyoxylate by the reaction with 2-methylthio-1,3-dithiane, followed by acetylation and ethanolysis. Introduction of an additional one carbon unit to the glyoxylate was accomplished by the Wittig reaction, and the subsequent hydrolysis and lactonization afforded 1-(2-hydroxy-4,4-dimethylcyclopentyl)-5-methylene-3-oxabicyclo[4.2.0]octan-4-one, which was transformed into 5-acetoxymethyl-5-hydroxy-1-[4,4-dimethyl-2-(tetrahydropyranyloxy)cyclopentyl]-3-oxabicyclo[4.2.0]-octan-4-one. Mesylation followed by elimination and oxidation led to (±)-dihydrofomannosin acetate.
Effects of Sodium Tetraborate as an Additive on the Reaction of α-Alumina with Sodium Carbonate
Authors: Chang Byong-Tae , Oh Jae-Gun , Om Suk-Ja 
Published: July 2006

Abstract
Effects of sodium tetraborate as an additive in the reaction of α-alumina with molten sodium carbonate have been studied mainly in a N2 atmosphere. Addition of sodium tetraborate accelerates the reaction, the α-alumina reacted increasing from 31.7% to 99.3% by addition of sodium tetraborate corresponding to the initial B2O3/Na2O molar ratio of only 1/15 under the other same conditions. By means of the Jander equation the activation energy was found to be 53 kcal/mol for the α-Al2O3–Na2CO3–Na2B4O7, system, which was lower by 10 kcal/mol than that for the α-Al2O3–Na2CO3 system. X-Ray diffraction and thermal data were analyzed in relation to the phase equilibrium of the melt.
The Chromatographic Concentration of Mercury in Sea Water with 2-Mercaptobenzothiazole Supported on Silica Gel
Authors: Terada Kikuo , Morimoto Kumiko , Kiba Toshiyasu 
Published: July 2006

Abstract
A solid chelating material, 2-mercaptobenzothiazole supported on silica gel (MBT-SG), was prepared and used for the preconcentration of inorganic and organic mercury compounds from a sea-water sample. The chelating capacity of the material was 12 μeq. Hg/g. The mercury (II) ion, the methylmercury ion, and the ethylmercury ion were quantitatively retained on the MBT-SG at pH values of 1.0, 5.0, and 4.0 respectively from an aqueous solution, and at pH values of 4.0, 4.5, and 5.0 respectively from a sea-water. A column packed with the material provided a quantitative recovery of these ions from a sea-water sample at a high flow rate (1–3 1 h−1). Mercury was eluted by the use of a acetone–hydrochloric acid mixture (25: 1) or a 1% thiourea solution in 0.1 mol dm−3hydrochloric acid. The latter effluent was submitted atomic-absorption spectrometry after reductive vaporization for the determination of mercury.
Binuclear Metal Complexes. XXXI. Synthesis and Magnetic Property of Binuclear Manganese(III) Complexes with 3-Salicylideneamino-1-propanol and Its Homologues
Authors: Torihara Naoyuki , Mikuriya Masahiro , Okawa Hisashi , Kida Sigeo 
Published: July 2006

Abstract
Binuclear manganese(III) complexes with 3-salicylideneamino-1-propanol and its homologues, MnL(ac) and MnLXH2O (L=Schiff base dianion; ac=acetate ion; X−=Cl−, Br−, N3−), were synthesized. It was shown that manganese(III) ions were bridged by the deprotonated alcoholic oxygen of the Schiff base in the equatorial plane and coordinated by bidentate acetate ion or X− and H2O groups in apical positions to form six-coordination. Cryomagnetic measurements indicated that an antiferromagnetic spin-exchange interaction operates between a pair of manganese(III) ions; exchange integral being evaluated at −13.5–−20.4 cm−1.
The Extraction of Several Anions by Methyltrioctylammonium into Various Solvents
Authors: Inoue Yasushi , Tochiyama Osamu 
Published: July 2006

Abstract
The back extraction of methyltrioctylammonium chloride (MTOACl) from ten kinds of organic solvents was investigated as a function of the MTOACl concentration. The chemical species of the ammonium salt in the organic phase were found to be in the form of dissociated ions, of ion pairs, or of dimeric ion pairs, according to the dielectric constant of the solvent. MTOACl was better extracted into more polar and acidic solvents, such as nitrobenzene, 3-methyl-1-butanol, and chloroform. The selectivity coefficients (KX/Cl) of MTOA for the exchange of Br−, I−, ClO4−, vs. Cl− were obtained from the study of the distribution of several organic color reagents; they were found to increase with the anion size, irrespective of the organic solvent used. For all but acidic solvents, the values of KX/Cl were similar to each other. Such acidic solvents as 3-methyl-1-butanol and chloroform, however, reduced the selectivity of the extraction for anions.
The Synthesis of Tedanin and Its Isomer, 3-Hydroxy-2,3-didehydro-β,φ-caroten-4-one
Authors: Yasuhara Mitsuki , Inanaga Kazuko , Kumae Takashi , Brahmana Hemat Rysona , Okukado Nobuhisa , Yamaguchi Masaru 
Published: July 2006

Abstract
The structure, 3-hydroxy-2,3-didehydro-β,χ-caroten-4-one, assigned to tedanin, the main carotenoid pigment of the marine sponge “Tedania digitata (O. Schmidt),” has been confirmed by total synthesis starting with β,χ-carotene. An isomer, 3-hydroxy-2,3-didehydro-β,φ-caroten-4-one, was also synthesized from β,φ-carotene.
Stereochemistry of Nucleophilic Addition Reactions. VIII. Preparation of 1,5-Anhydro-4,6-O-benzylidene-2,3-dideoxy-3-nitro-d-erytho-hex-2-enitol and Its Reactions with Some Nucleophiles
Authors: Sakakibara Tohru , Nomura Yutaka , Sudoh Rokuro 
Published: July 2006

Abstract
The title compound was synthesized from 1,5-anhydro-d-glucitol via nitromethane cyclization. The reduction of the compound with sodium borodeuteride afforded a mixture of saturated nitro compounds having an axial and equatorial deuterium atom at C-2 in an approximate ratio of 2:1. On the other hand, the reaction with hydrogen cyanide gave predominantly the adduct with the manno configuration, together with small amounts of a cyano olefin. The reaction with hydrazoic acid yielded addition products with the gluco and manno configurations; the ratio was strongly affected by the solvent used.
The Reactions of (1-Halo-1-alkenyl)dialkylboranes with Lead(IV) Acetate or (Diacetoxyiodo)benzene. A Stereoselective Synthesis of 1-Halo-1,2-dialkylethylenes
Authors: Masuda Yuzuru , Arase Akira , Suzuki Akira 
Published: July 2006

Abstract
The reaction of (1-halo-1-alkenyl)dialkylboranes with lead(IV) acetate or (diacetoxyiodo)benzene was studied. (1-Bromo-1-alkenyl)dialkylboranes gave 1-bromo-1,2-dialkylethylenes. When alkyl groups on the boron atom of vinylboranes were bulky or the reaction temperatures were low, Z-isomers were afforded, whereas when alkyl groups on the boron atom were small or the reaction temperatures were relatively high, E-isomers were afforded as the main products. (1-Chloro-1-alkenyl)dialkylboranes gave (Z)-1-chloro-1,2-dialkylethyienes regardless of the reaction conditions. (1-Iodo-1-alkenyl)dialkylboranes failed to give satisfactory yields of 1-iodo-1,2-dialkylethylenes.
Enolate Anions. II. Substituent Effects of Sodium Ethyl Phenylacetates in DMSO
Authors: Kiyooka Syun-ichi , Ueda Yoshinobu , Suzuki Kojiro 
Published: July 2006

Abstract
The UV-visible, IR, and 1H-NMR spectra of the sodium enolates of ethyl phenylacetates (substituents; p-CH3O, p-CH3, m-CH3, H, p-Cl, p-CH3CO, m-CH3CO, p-COOC2H5, p-CN, and p-NO2) in DMSO were measured at room temperature. The derivatives with electron-attracting groups at the para position exhibit their absorption maxima with ε&gt;104 in visible regions above 400 nm. The visible spectra suggest the presence of a resonance between their electron-attracting groups at the para position and the enolate anion parts through the benzene ring. The carbonyl-stretching vibrations of the enolates in the IR spectra and the chemical shifts of the residual methine proton of the enolates in the 1H-NMR spectra can be well explained by using the substituent constants, σ and σ−. The ρ values of the meta and para lines are extremely different. In the case of the p-NO2 derivative, the 1H-NMR spectra of the benzene-ring protons indicate that the free rotation of the partially double bond between the benzene ring and the enolate-anion part is fixed at room temperature.
The Reaction of Alkenylboranes with Palladium Acetate. Stereoselective Synthesis of Olefinic Derivatives
Authors: Yatagai Hidetaka 
Published: July 2006

Abstract
The reactions of alkenylboranes with palladium acetate were investigated. Alkenyldialkylboranes, derived from terminal alkynes, underwent intramolecular migration reaction in the presence of an equimolar amount of palladium acetate and triethylamine to give (E)-olefins. On the other hand, under the same conditions as above or even in the presence of catalytic amounts of palladium acetate, alkenyldialkylboranes derived from internal alkynes underwent protonolysis reaction to produce (Z)-olefins. An alkenylpalladium intermediate which was presumably involved in the latter reaction was trapped by allylic chloride to give 1,4-dienes.
Photochemical Reactions of Dicyanobenzenes with Aliphatic Amines
Authors: Ohashi Mamoru , Miyake Kentaro , Tsujimoto Kazuo 
Published: July 2006

Abstract
Upon irradiation, p-dicyanobenzene reacted with primary, secondary, and tertiary aliphatic amines to give substitution products in which one of the cyano groups was replaced by the amine at α-CH position or by an alkyl group of the amine. o-Dicyanobenzene reacted similarly, but the meta-isomer did not react under similar conditions. The rates of the fluorescence quenching of p-dicyanobenzene with the amines are close to the diffusioncontrolled rate, but are somewhat dependent on the ionization potentials of the amines. When the substitution product was irradiated, the corresponding alkylation product was obtained. The mechanisms of these reactions have been investigated by the use of such proton donors as MeOH(MeOD); on the basis of those investigations, new photochemical reactions involving charge-transfer, followed by proton-transfer and then addition-elimination, are proposed, as well as a new type of photo-induced Birch reduction.
Abnormal Nazarov Reaction. A New Synthetic Approach to 2,3-Disubstituted 2-Cyclopentenones
Authors: Hirano Shigeo , Takagi Seiji , Hiyama Tamejiro , Nozaki Hitosi 
Published: July 2006

Abstract
Acid-catalyzed reaction of β,β′-disubstituted cross conjugated dienones or the corresponding ethylene acetals gives mainly 2,3-disubstituted 2-cyclopentenones in stead of the simple Nazarov cyclization products, 3,4-disubstituted 2-cyclopentenones. This transformation is explained in terms of electrocyclic ring-closure, addition of hydroxylic solvent(s), tautomerization of the resulting 2-hydroxycyclopentanone intermediates, followed by solvolysis and isomerization. Based on this working hypothesis a new route to jasmonoids is disclosed which involves acid-treatment of the acyloin disilyl ethers derived from substituted glutarates.