bluuebunny/crossref_metadata_2025 huggingface dataset:
Paramagnetic Cobalt(III) Complexes with Organic Ligands. VI. An X-Ray Photoelectron Spectroscopic Study
Authors: Yamamoto Yoshihisa , Mori Masayasu , Konno Hidetaka
Published: July 2006

Paramagnetic tetraammine-5-nitrosalicylato cobalt complex, paramagnetic μ-hyperoxo-dicobalt complexes and related diamagnetic compounds have been studied by X-ray photoelectron spectroscopy. In all these compounds, the binding energies of Co 2p electrons and their spin-orbit separation were those of usual Co(III) complexes. In the spectrum of paramagnetic tetraammine-5-nitrosalicylatocobalt salt, satellites appeared near the Co 2p peaks showing certain spin density at the cobalt atoms. At the same time, the C ls spectrum showed that considerable portion of carbon atoms has high binding energy suggesting delocalization of electron hole over the organic ligand. The O ls peaks in μ-hyperoxo complexes were ca. 0.6 eV higher than those in μ-peroxo complexes. Deconvolution of the O ls peak in the μ-OOH complex gave OH, =O–, and H2O peaks at the 1:1:1 ratio, supporting the μ-OOH formulation.
The Gibbs Energies, Enthalpies, and Entropies of the Dilution of Aqueous Sodium Chondroitin-4-sulfate and -6-sulfate
Authors: Yonese Masakatsu , Tsuge Hideya , Kishimoto Hiroshi
Published: July 2006

The osmotic coefficients of a solvent, φ, in aqueous solutions of sodium chondroitin-4-sulfate (NaChS-A) with a relatively low molecular weight and -6-sulfate (NaChS-C) with various molecular weight were measured by means of vapor-pressure osmometry. The molar Gibbs energes of dilution, ΔdilG were determined from the thermodynamic analysis of the φ values. The molar entropies of dilution, ΔdilS were calculated through the substitution of the molar dilution enthalpies, ΔdilH which had been measured previously, into ΔdilG. These thermodynamic quantities of dilution were discussed by taking Manning’s limiting law into consideration. The concentration and temperature dependencies of the observed ΔdilH agreed well quantitatively with those of the electrostatic ΔdilH calculated by Manning’s limiting law, when the distance between the neighboring charges of the polyion, b, was assumed to be 4.8 Å, whereas the observed ΔdilG and ΔdilS values did not agree quantitatively with the theoretical ones based on electrostatic interactions. From a comparison of the experimental ΔdilS values with the theoretical ones, the non-electrostatic dilution entropy was evaluated and discussed.
Preparation and Properties of Monoalkylnickel(II) Complexes Having a Phenoxo, Benzenethiolato, Oximato, β-Diketonato, or Halo Ligand
Authors: Yamamoto Takakazu , Kohara Teiji , Yamamoto Akio
Published: July 2006

Thirteen complexes of a type NiR(Y)Ln (R=CH3 (Me), C2H5 (Et); Y=OC6H5, p-cyanophenoxo, 8-phenylphenoxo, 8-quinolinolato, OCOEt, OCOPh, acetophenone oximato, acetylacetonato, benzoylacetonato, Cl; L=trie thy lphosphine (PEt3), 2,2′-bipyridine (bpy)) have been prepared by reactions of dialkylnickel(II) complexes NiR2L2 (1) with the corresponding active hydrogen compounds HY. Reactions of 1 with R′COY (Y=OC6H5, OCOC6H5, Cl) also afford the NiR(Y)Ln type complexes with formation of unsymmetrical ketones RCOR′. Reactions of 1 with alcohols lead to dehydrogenation of alcohols to afford aldehydes or ketones. The NiR(Y)Ln type complexes have been characterized by elemental analysis and spectroscopies (IR, NMR, visible). NMR spectra of trans-NiMe(OCOPh)(PEt3)2, NiMe(acetophenone oximato)(PEt3) (11), NiMe(benzoylacetonato) (PEt3) show temperature dependence, indicating occurrence of rapid dynamic reactions on NMR time scale in these complexes. The acetophenone oximato ligand in 11 is proposed to serve as an oxa-, aza-π-allylic ligand on the bases of IR and NMR spectroscopies. NiEt(OCOC2H5)(bpy) (8), NiEt(OCOC6H5)(bpy), and NiEt(Cl)(bpy) (14) undergo disproportionation reaction to give NiEt2(bpy) and NiY2(bpy) type complexes. Diethyl ketone is also produced during the disproportionation of 8. Reactions of 14 with olefins having electron-withdrawing substituents afford NiCl2(bpy) and Ni(olefin)2(bpy).
The Polarographic Behavior of Bis(acetylacetonato)nickel(II) and Bis(hexafluoroacetylacetonato)nickel(II) in Dimethyl Sulfoxide
Authors: Kudo Setsuko , Iwase Akio , Tanaka Nobuyuki
Published: July 2006

The d.c. polarographic reduction of Ni(acac)2 and Ni(hfac)2 was studied in detail in dimethyl sulfoxide. Two kinds of tetraalkylammonium perchlorates and sodium perchlorate were used as supporting electrolytes. Ni(acac)2 gave three waves in all the supporting electrolytes, while Ni(hfac)2 gave two waves in the presence of tetraalkylammonium perchlorate. These waves were explained on the basis of the polarographic properties, molecular weights, and conductivities. The electrode reaction mechanism of Ni(acac)2 can be expressed by:

(Remark: Graphics omitted.)

where the second wave includes a kinetic current. The first wave of Ni(hfac)2 is due to the reduction of Ni(hfac)+ and Ni(hfac)2 themselves; the second wave corresponds to that of free hexafluoroacetylacetonate.
Applications of Homogeneous Water-gas Shift Reaction. III. A Further Study of the Hydrocarbonylation. A Highly Selective Formation of Diethyl Ketone from Ethene, CO, and H2O
Authors: Murata Kazuhisa , Matsuda Akio
Published: July 2006

The hydrocarbonylation of ethene with CO and H2O produces diethyl ketone with a high selectivity of 99±1%(propanal 1±1%); a Co2(CO)8–phosphine system is used as an efficient catalyst, which is also active for the homogeneous water-gas shift reaction. The effects of the reaction parameters(CO pressure, temperature, and ethene and H2O concentrations) on the selectivity and activity are examined for the Co2(CO)8–1,2-bis(diphenylphosphino)ethane (diphos) system; the selectivity to yield the ketone is fairly high under the variety of conditions studied here. Evidence suggests that the active species which catalyze the water-gas shift reaction participate in the hydrocarbonylation of ethene.
Stereospecific and Stereoselective Reactions. V. Alkylation of Active Methylene Compounds by the Use of Alcohols, Diethyl Azodicarboxylate, and Triphenylphosphine
Authors: Kurihara Toshio , Sugizaki Masaru , Kime Itaru , Wada Makoto , Mitsunobu Oyo
Published: July 2006

The reagent formed by the reaction of diethyl azodicarboxylate (1) and triphenylphosphine (2) reacted with alcohols and ethyl cyanoacetate (6) to give alkylated products in 30–80% yields. When ethyl acetoacetate, 1,3-cyclopentanedione, or 1,3-cyclohexanedione was used in place of 6, the corresponding O-alkylated products were obtained. The reaction of either (S)-(−)-ethyl lactate or (S)-(−)-ethyl 2-hydroxy-3-phenylpropionate with 1, 2, and 6, followed by hydrolysis resulted in the formation of (S)-(−)-methylsuccinic acid or (S)-(−)-benzylsuccinic acid. The results indicate that nearly complete inversion of the configuration takes place in the alkylation step.
Asymmetric Reactions. X. Asymmetric Hydrogenation Catalyzed by Bis(dimethylglyoximato)cobalt(II)–Chiral Cocatalyst (Amino Alcohol) System
Authors: Ohgo Yoshiaki , Takeuchi Seiji , Natori Yukikazu , Yoshimura Juji
Published: July 2006

The catalytic asymmetric hydrogenations of α-diketones, α-keto carboxylates, α-(acylamino)acrylates, α-phenylacrylophenone, and α-phenylacrylate were examined with bis(dimethylglyoximato)cobalt(II)–chiral cocatalyst (amino alcohol) and with simple achiral base coordinated bis(dimethylglyoximato)cobalt(II)–chiral cocatalyst (amino alcohol) systems. These gave corresponding optically active reduction products, and in some cases, optically active reductive dimerization products. High degrees of enantioselectivities (≈78%) are achieved in the hydrogenation of α-diketones. Evidence for non-binding of chiral base to cobalt complexes was presented in the case of latter system, i.e., it was shown that the catalytic site and the enantioselectivity-determining site are separated in this system, as in enzymes. The importance of protonated chiral bases for enantioselection was also shown. Based on these results and the stereochemical correlations between structures of the chiral bases and those of the products, a mechanism for this asymmetric hydrogenation was proposed.
Structure of Octa-O-acetyl-tris(N-ethoxycarbonyl)destomycin A
Authors: Horito Shigeomi , Ohashi Yuji , Gassner Nobert , Yoshimura Juji , Sasada Yoshio
Published: July 2006

The molecular and crystal structure of octa-O-acetyl-tris(N-ethoxycarbonyl)destomycin A tetrahydrate, C45H65N3O27·4H2O, has been determined by X-ray analysis. The space group is P21 with a=14.738(4), b=17.391(4), c=12.171(4) Å, β=105.58(4)°, and Z=2. The structure was solved by the direct method, and the least-squares refinement using 4008 reflections led to the final R value of 0.12. The configuration of the ortho ester carbon atom is (R). The d-talose moiety has the boat conformation whereas the other rings are in the chair form.
Reaction of Organoaluminium Reagents with Cyclopropylmethyl Acetates and 2-Vinylcyclopropane-1,1-dicarboxylate Esters
Authors: Hiyama Tamejiro , Morizawa Yoshitomi , Yamamoto Hajime , Nozaki Hitosi
Published: July 2006

Ring-opening alkylation of cyclopropylmethyl acetates was studied. The acetoxyl group of 7-(1-acetoxyheptyl)norcarane is substituted by the alkyl group upon treatment with trialkylaluminium, but alkylation of trans-1-(1-acetoxyethyl)-2-phenylcyclopropane with trialkylaluminium gives rise to trans-5-phenyl-2-alkenes. The reaction of (1S,2S)-2-phenylcyclopropylmethyl acetate with trimethylaluminium resulted in the complete loss of optical activity to give racemic 4-phenyl-1-pentene. Alkylation of trans-1-(1-acetoxy-3-phenylpropyl)-2-vinylcyclopropane with trialkylaluminium proceeds under regioselective ring-opening to give 3-alkylated trans-8-phenyl-1,5-octadiene (selectivity 73–83%). The regio- and stereochemistry of homoconjugate addition to activated vinylcyclopropanes having a doubly carbonyl substituted ring carbon was studied. Trialkylaluminium on addition to diethyl 2-vinylcyclopropane-1,1-dicarboxylate in a 1,5-manner afford diethyl (2-alkyl-3-butenyl)propanedioate (over 96% selectivity). In contrast, the reaction of this cyclopropane with tetraalkylaluminiumlithium takes place in a 1,7-manner to give diethyl (trans-4-alkyl-2-butenyl)propanedioate with 88–92% selectivity. Clean regiocontrol of the reaction is observed in the methylation of ethyl exo-6-(trans-1-propenyl)-2-oxobicyclo[3.1.0]hexane-1-carboxylate with trimethylaluminium or tetramethylaluminiumlithium. Alkylation with trimethylaluminium proceeds with 86% inversion of the configuration at C(6) of the substrate, affording (2R*,3R*)-2-ethoxycarbonyl-3-[(S*)-trans-1-methyl-2-butenyl]cyclopentanone which is transformed into neonepetalactone.
Branched-chain Sugars. XXII. Synthesis of Benzyl 2,3-Di-O-benzyl- and 2,3-O-Methylene-β-l-threo-pentopyranosid-4-uloses, and the Corresponding 6-Deoxy-α-d-xylo-hexopyranosid-4-uloses
Authors: Matsuzawa Masafumi , Kubo Kazusuke , Kodama Hisashi , Funabashi Masuo , Yoshimura Juji
Published: July 2006

The title compounds were synthesized from l-arabinose and d-glucose as intermediates to a few naturally occuring branched-chain sugars. Oxidation conditions of precursors to the corresponding 4-uloses were examined.
Syntheses of [1]Benzopyrano[4,3-c]pyrazoles and -[3,4-d]isoxazoles
Authors: Shimizu Tomio , Hayashi Yoshiyuki , Yamada Kazunari , Nishio Toshiyuki , Teramura Kazuhiro
Published: July 2006

The reaction of 2H-1-benzopyran with several 1,3-dipoles gives cycloadducts in good yields. The orientation of the cycloaddition is qualitatively interpreted in terms of FMO theory. These heteropolycyclic compounds were also obtained from hydrazones of 3-aroyl-2H-1-benzopyrans, prepared from 3-cyano-2H-1-benzopyran.
Mixed Monolayers of Long Normal-chain Fatty Acids with Long Normal Alkyl Esters. III. Pentadecanoic Acid-Esters System
Authors: Matuo Hirosi , Motomura Kinsi , Matuura Ryohei
Published: July 2006

The surface pressures of mixed monolayers of pentadecyl acetate, hexadecyl acetate, heptadecyl acetate, and hexadecyl propionate with pentadecanoic acid were measured at various compositions and temperatures. The two-dimensional phase diagram and apparent molar entropy and energy changes were evaluated by means of a previously described thermodynamic treatment. They depend uniquely on the molecular structure of the film-forming substances and on the composition in the mixed monolayer. The phase diagrams of pentadecanoic acid–pentadecyl acetate and pentadecanoic acid–hexadecyl acetate systems are of a complicated type. There are positive and negative regions in the excess apparent molar energy changes. The pentadecanoic acid–heptadecyl acetate and pentadecanoic acid–hexadecyl propionate systems are of the positive azeotropic type. The excess apparent molar energy changes are positive over the whole range of mole fractions.
The Enantioface-differentiating (Asymmetric) Hydrogenation of the C=O Double Bond with Modified Raney Nickel. XXXVI. The Development of Modified Nickel Catalysts with High Enantioface-differentiating Abilities
Authors: Harada Tadao , Yamamoto Mihoko , Onaka Shinji , Imaida Motomasa , Ozaki Hiroshi , Tai Akira , Izumi Yoshiharu
Published: July 2006

Various types of modified nickel catalysts were prepared and their enantioface-differentiating (asymmetric) abilities were examined. It was found that the presence of aluminum or related metal compounds in the catalyst was unfavorable for the effective enantioface-differentiating catalyst. The modification with a solution containing tartaric acid and inorganic salt gave a high enantioface-differentiating ability to Raney nickel and reduced nickel catalyst. Among the modified nickel catalysts examined, the Raney nickel modified with tartaric acid and sodium bromide gave the best result with respect to the hydrogenation activity and enantioface-differentiating ability (optical yield 88%). NaBr adsorbed on Raney nickel was found to inhibit the nonenantioface-differentiating hydrogenation.
Oxygenation of Aromatic Vinyl Ethers. A Noticeable Formation of Epoxides and Reaction Mechanism
Authors: Kanno Tatsuya , Hisaoka Motoyuki , Sakuragi Hirochika , Tokumaru Katsumi
Published: July 2006

cis-β-Alkoxystyrenes such as cis-β-methoxy-, cis-β-ethoxy-, and cis-β-isopropoxystyrene were autoxidized as neat at room temperature in the dark even in the absence of any radical generator. UV-irradiation and the use of a radical generator facilitated the oxygenation of these olefins. These oxidations afforded the corresponding epoxides or their derivatives in considerable yields as well as carbonyl compounds resulting from oxidative cleavage of the double bonds. The mechanisms for these oxidations are proposed to involve free-radical chain pathways and charge-transfer complexes between the olefins and oxygen which play an important role in the initiation steps.
Migrated Lupane Derivatives. Boron Trifluoride Etherate-catalyzed Backbone Rearrangement of 3α,4α- and 3β,4β-Epoxy- D : A-friedo-18β,19αH-lupanes and Solvent Effects
Authors: Yokoyama Yasushi , Moriyama Yoshihiko , Tsuyuki Takahiko , Takahashi Takeyoshi
Published: July 2006

Backbone rearrangements of 3α,4α- and 3β,4βepoxy-D:A-friedo-18β,19αH-lupanes catalyzed by boron trifluoride etherate gave 18β,19αH-lup-12-en-3-ols, lup-18-en-3-ols, and lup-19-en-3-ols, besides known D:B-friedo-18β,19αH-lup-5-en-3-ols and -5(10)-en-3-ols. D:B-Friedo-18β,19αH-lup-l(10)-en-3α-ol and 3β,10β-epoxy-D:B-friedo-18β,19αH-lupane were also obtained from α- and β-epoxides, respectively. Solvent effects on these reactions were examined.
Oxidative Cleavage Reaction of 3-Substituted Indoles Catalyzed by CuCl–Pyridine Complex under Oxygen
Authors: Tsuji Jiro , Kezuka Hiroaki , Takayanagi Hiroshi , Yamamoto Keiji
Published: July 2006

Oxidative cleavage of 3-methylindole using a catalytic amount of copper(II) salts with added pyridine under an oxygen atmosphere was studied. Smooth cleavage of 3-methylindole took place to give 2-formamidoacetophenone in 73–80% yield, whereas exclusive formation of a hydrate compound derived from 3,3′-dimethyl-3,3′-bi-3H-indole resulted under anaerobic conditions. Clean oxidative cleavage of N-acetyltryptamine, methyl 3-indolylacetate, and methyl 2-acetamido-3-(3-indolyl)propionate was also achieved, constituting a mimic of tryptophan-2,3-dioxygenase.
Restricted Rotation Involving the Tetrahedral Carbon. XXXIX. 9-(2-Methoxy-1-methylethyl)triptycene Derivatives
Authors: Suzuki Masahiko , Yamamoto Gaku , Kikuchi Hiromi , Oki Michinori
Published: July 2006

9-(2-Methoxy-1-methylethyl)triptycenes were prepared from 9-(2-methoxy-1-methylethyl)anthracene and corresponding benzynes to examine the feasibility of isolating rotational isomers of 9-isopropyltriptycene derivatives at room temperature. They afforded crystalline ap forms which underwent internal rotation with activation energies of ca. 23 kcal/mol. 9-(2-Acetoxy-1-methylethyl)-1,2,3,4-tetrachlorotriptycene gave similar results. Based on the results, the barrier to rotation of 9-isopropyl-1,2,3,4-tetrabromotriptycene was reexamined to show that it must be corrected as 23.5 kcal/mol at 175 °C.
Configuration and Conformation of the Photoisomers of N-[p-(Dimethylamino)benzylidene]anilines
Authors: Yoshida Masato , Kobayashi Michio
Published: July 2006

The UV, 1H-NMR, and 13C-NMR spectra of the photoisomers produced by irradiation of N-[p-(dimethylamino)benzylidene]anilines at low temperature have been studied. The results suggested that the photoisomers have Z structures and the imino benzene rings are twisted around the Ar–N axis out of Ar–CH=N plane due to the steric repulsion between the two rings.
Spectroscopic Studies of Surfactant Solubility. III. Side-chain Effects of Phosphatidyl Compounds in Chloroform Solutions
Authors: Okazaki Mitsuyo , Hara Ichiro , Tsutsui Yumiko K , Fujiyama Tsunetake
Published: July 2006

The infrared spectra of phosphatidyl and related compounds were studied with respect to their side-chain effects on solubility. It was clarified that the existence of a hydrogen-bonding between chloroform and a phosphate group is essential for these phosphatidyl compounds to form stable solutions in chloroform. The existence of double alkyl-chains and acyloxyl groups is clarified to be very useful for those compounds to have a strong solvent-phobic character without losing their solubility in solvents. The role of a choline moiety was also clarified. The details of the analysis of the infrared intensity were also described. It was emphasized that the intensity enhancement due to hydrogen-bond formation can be quantitatively related to the enthalpy change due to hydrogen-bond formation.
The Reaction of Diazo Ketones in the Presence of Metal Chelates. VIII. The Stereochemistry of the 1,3-Dipolar Cycloaddition of 1-Methoxy- 2-benzopyrylium-4-olates to Ethylenic Dipolarophiles
Authors: Ibata Toshikazu , Jitsuhiro Kimiko , Tsubokura Yoshie
Published: July 2006

1,3-Dipolar cycloadducts were obtained in the reactions of 1-methoxy-2-benzopyrylium-4-olate (3a) with ethylenic dipolarophiles, such as dimethyl fumarate, dimethyl maleate, maleic anhydride, trans-1,2-dibenzoylethylene, N-substituted maleimides, and acenaphthylene. The configuration of the adducts was determined on the basis of the NMR coupling pattern of the methine protons of the adducts in connection with a deuterium experiment. The previously reported structure of the adduct of 3a with dimethyl fumarate was corrected according to the experimental results obtained using 3-deuterated 3a. The stereospecificity of the cycloaddition was confirmed in the reactions of dimethyl fumarate, dimethyl maleate, and trans-1,2-dibenzoylethylene; this stereospecificity was explained by the concerted (π2S+π4S) mechanism. The exo/endo ratios of the adducts of N-substituted maleimides may be explained by the combination of the steric repulsion and π-π interaction of the phenyl ring of 3 and the substituent on the N-atom of maleimides. The cycloadditions of 1-methoxy-3-methyl-2-benzopyrylium-4-olate with N-substituted maleimides were also explained in a similar manner.
On the Extractability of Univalent Cation as Dibenzo-18-crown-6 Complexes with Picrate Ion
Authors: Hasegawa Yuko , Wakabayashi Hiroji , Sakuma Manabu , Sekine Tatsuya
Published: July 2006

The solvent extractions of alkali metal(I) with dibenzo-18-crown-6 (the nomenclature recommended by IUPAC is 2,3,1l,12-dibenzo-1,4,7,10,13,16-hexaoxacyclooctadeca-2,11-diene) as the picrate into chloroform and benzene were studied at 25°C and compared with those of other univalent ions. The extraction constants of the metal ions (Kex0=[ME+A−]org[M+]−1[E]org−1[A−]−1), are in the sequence of Tl+\simeqK+>Rb+>NH4+≥Ag+>Cs+>Na+, but the extraction constants of the metal complexes (Kex=[ME+A−]org×[ME+]−1[A−]−1) are NH4+\simeqTl+\simeqRb+\simeqK+>Cs+\simeqAg+>Na+.
Visible Light-induced Oxidation of Ascorbic Acid and Formation of Hydrogen Peroxide
Authors: Kurimura Yoshimi , Yokota Hiroshi , Muraki Yuko
Published: July 2006

Photosensitized oxidation of ascorbic acid and the formation of hydrogen peroxide using tris(2,2′-bipyridine)ruthenium(II), Ru(bpy)32+, proceed simultaneously in oxygen containing an aqueous solution of ascorbic acid with the illumination of visible light. The mechanism of the reaction has been suggested from the rate dependence on the solute concentrations and from quenching experiments. The charge separation could be achieved as the result of scavenging Ru(bpy)33+, which is formed by the reaction of the lowest excited state species of Ru(bpy)32+ with O2.
X-Ray Structures of Di-μ-oxo, μ-Oxo-μ-thio-, and Di-μ-thio-μ-[(R)propylenediaminetetraacetato]-bis[oxomolybdate(V)] Ions
Authors: Kojima Akinobu , Ooi Shun’ichiro , Sasaki Yoichi , Suzuki Kimiko Z , Saito Kazuo , Kuroya Hisao
Published: July 2006

The crystal structures of Na2[Mo2O4(R-pdta)]·3H2O (1), Na2[Mo2O3S(R-pdta)]·4H2O (2), and Na2[Mo2O2S2(R-pdta)]·4H2O (3) have been determined from difTractometer data collected by the use of Mo Kα radiation. The structures of 1, 2, and 3 were refined by the least-squares method to R 0.064, 0.040, and 0.058 for 1370, 2794, and 2141 nonzero reflections respectively. Each Mov ion has a distorted octahedral coordination, and the two coordination octahedra share a common edge to form a binuclear complex. Two terminal oxo ligands are cis to the bridging oxide or sulfide. The R-pdta4− ligand bridges two Mov ions, yielding a Mo–N–CH2–CH(CH3)–N–Mo ring with an equatorial methyl group, the N and carboxyl O atoms occupying the axial (trans to the terminal O) and equatorial positions respectively. A specific distortion of the donor-atom disposition is observed, which is represented as the twist (Δ) of the terminal O–O edges in the (Remark: Graphics omitted.) portion about the axis passing through the mid-points of the O–O edges (Δ denotes the absolute disposition of two skew edges or bonds), and as the twist (Δ) of Mo–N bonds about the Mo–Mo axis. The O=Mo bonds of the O=Mo–Mo=O segment in 1 twist in Δ, but those in 2 and 3 are virtually parallel. The distortion of donor-atom disposition is discussed on the basis of the strain due to chelate-ring formation.
Kinetic Studies of Fast Equilibrium by Means of High-performance Liquid Chromatography. II. Ligand Exchange of N,N-Disubstituted Dithiocarbamate Chelates of Ni(II)
Authors: Moriyasu Masataka , Hashimoto Yohei
Published: July 2006

The equilibrium of the ligand exchange of labile Ni(II) dialkyldithiocarbamate chelates (MA2+B\ightleftharpoonsMAB+A, MAB+B\ightleftharpoonsMB2+A, K1=[MAB][A]/[MA2][B], K2=[MB2][A]/[MAB][B]) has been investigated by means of high-perfromance liquid chromatography, two solutions of MA2 and B being mixed and then equilibrated. The equilibrium constants, K1 and K2, have been determined by measuring the concentrations of each complex, including the kinetically unstable ternary complex in the equilibrium state. The ratio of the stability constants of the two Ni(II) chelates, which is equal to K1K2, has been calculated. The following series of increasing stability constants has been found for the alkyl substituents in chloroform; tetramethylene<dimethyl<pentamethylene<diethyl<hexamethylene<dipropyl<dibutyl. The rate of ligand exchange has been investigated by mixing very dilute MA2 and B and by injecting the mixture into HPLC after the lapse of a certain time. The rate of ligand exchange is slow when low initial concentrations of MA2 and B are chosen. The rate of ligand exchange is more than ten times faster than that of ternary complex formation.
Applications of Homogeneous Water-gas-shift Reaction. II. The Formation of Dipropyl Ketones as Primary Products from CO and H2O in the Presence of an Excess Amount of Propene. Cobalt-based Catalytic Hydrocarbonylation
Authors: Murata Kazuhisa , Matsuda Akio
Published: July 2006

The hydrocarbonylation of propene with CO and H2O to give dipropyl ketones occurs predominantly over forming C4-aldehydes; the catalyst solutions employed are prepared in situ from Co2(CO)8, various phosphines as ligands, and H2O, a high molar ratio of propene to Co2(CO)8 of 300/2 being required. Of the several phosphorus ligands examined, 1,2-bis(diphenylphosphino) ethane (diphos) and bis(diphenylphosphino) acetylene are relatively effective for the formation of the ketones (abbreviated as [ketones]). The effects of the reaction variables (CO pressure, temperature, and H2O concentration) on [ketones] are also examined using the Co2(CO)8–diphos system; [ketones] increases with the initial increase in CO pressure, but reaches a maximum at ca. 100 kg/ cm2 and decreases thereafter. Pronounced decreases of [ketones] are observed when pyridine as well as hydrogen is added to the catalyst solutions.
The Oxidation Products of Tetracyanoferrate(II) Chelates with Optically Active 1,2-Diamines: Tetracyano(1,2-diamine)ferrate(III)s and Tetracyano(1,2-diimine)ferrate(II)s
Authors: Goto Masafumi , Takeshita Michihiro , Sakai Tomoya
Published: July 2006

Optically active diamagnetic title complexes were oxidized with hydrogen peroxide under acidic and basic aqueous conditions. The corresponding low-spin tetracyano(diamine)ferrate(III) complexes with (R)-1,2-propanediamine, (1R,2R)-1,2-cyclopentanediamine, and (1R,2R)-1,2-cyclohexanediamine as diamines formed under acidic conditions and were characterized with several spectral measurements including the CD spectra. Each CD spectrum showed a moderate positive Cotton effect at ca. 24700 cm−1 and was assigned to a d-d transition. However a ligand oxidation took place, yielding tetracyano(1,2-diimine)ferrate(II) complexes under neutral and basic conditions; their electronic and 1H- and 13C-NMR spectra are also reported.
Preparation of (E)-1,3,5-Hexatriene and (3E, 5E)-1,3,5,7-Octatetraene by the Palladium Catalyzed Elimination of Acetic Acid from Allylic Acetates
Authors: Yamamoto Keiji , Suzuki Shigeaki , Tsuji Jiro
Published: July 2006

Palladium complex-catalyzed elimination of acetic acid from (2E,4E)-2,4-hexadienyl acetate and (2E, 4E, 6E)-2,4,6-octatrienyl acetate afforded, respectively, the title conjugated polyenes stereoselectively.
Pressure and Temperature Dependence of NMR Spin-lattice Relaxation in Plastic 2,2-Dimethylpropanoic Acid
Authors: Hasebe Tooru , Soda Gen , Chihara Hideaki
Published: July 2006

Proton spin-lattice relaxation time T1 of 2,2-dimethylpropanoic acid in its plastic phase was measured at 10 MHz up to 120 MPa between 268 K and 330 K. A minimum in T1 appears in the low-pressure region which is due to overall reorientation of molecules. The T1 minimum value decreases as the pressure increases in a way different from simple-minded prediction. The activation volume, 25±3 cm3 mol−1, is twice as large as in other plastic crystals when normalized by the molar volume. The pressure dependence of the activation enthalpy is also about twice as large. These can be rationalized by considering associated dimers as the reorienting unit. The phase diagram is given and the volume changes associated with the transition and with the fusion were derived (15.6 and 5.86 cm3/mol of dimer).
1,3-Dipolar Cycloaddition Reaction of Vinyl Azides with Enamines. Synthesis of Vinyltriazolines and Vinyltriazoles
Authors: Nomura Yujiro , Takeughi Yoshito , Tomoda Shuji , Ito Masato M
Published: July 2006

Reaction of α- and β-azidostyrene with enamines gave vinyltriazolines regioselectively in moderate yields. 1-Pyrrolidinyl enamines reacted with α-azidostyrene more readily than piperidino or morpholino enamines. β-Azidostyrene was as reactive as azidobenzene while α-azidostyrene was much less reactive. Vinyltriazolines formed from enamines of ketones were deaminated to yield the corresponding vinyltriazoles.
ESR Spectra and Structure of the Radical Anions of Organo Halosilanes
Authors: Hasegawa Akinori , Nagayama Akihiro , Hayashi Michiro
Published: July 2006

The radical anions of ethyl- and vinyl- halosilanes formed in solid matrices of tetramethylsilane and their ESR spectra were investigated to be compared with results obtained from related radical anions. These radical anions have a trigonal bipyramidal structure with two axial and two equatorial positions. Ethyl and methyl groups which are less electronetative than H prefer the equatorial positons. The vinyl group with a single π electron system occupies the equatorial position due to its electron-donating capability, in spite of its larger electronegativity.
The Capillary-tube Isotachophoretic Determination of Sodium(I), Magnesium(II), Calcium(II), Strontium(II), and Barium(II) Using Complex-forming Equilibria between CyDTA and the Metal Ions
Authors: Nukatsuka Isoshi , Taga Mitsuhiko , Yoshida Hitoshi
Published: July 2006

The capillary-tube isotachophoresis technique was used to determine sodium(I), magnesium(II), calcium(II), strontium(II), and barium(II). The complex-forming equilibria between CyDTA and the metal ions were used to expand the differences among their effective mobilities. The mobilities of IIa metal ions decreased with increases in the pH of the leading electrolytes and in the CyDTA concentration in the leading electrolytes. The simultaneous determination of the above five cations could be performed when the pH of the leading electrolyte was adjusted at 5.5 or above. The relative standard deviations were 1.7–2.2% for determining 15.0–25.0 nmol of the cations when the pH of the leading electrolyte was 5.70. Magnesium(II) and calcium(II) ions underwent “enforced isotachophoretic” migration.
The Spectrophotometric Determination of Ethylene Diamine with Phthalaldehyde and 2-Mercaptoethanol
Authors: Hihara Goro , Miyamae Hiroshi , Nagata Miharu
Published: July 2006

A simple spectrophotometric method has been developed for the determination of ethylenediamine in an aqueous or ethanolic solution. This method is based on the reaction of ethylenediamine with phthalaldehyde and 2-mercaptoethanol, and on the measurement of the absorbance of the yellow-developed solution at 430 nm. Beer’s law holds for 0.5–10 μg of ethylenediamine per 1 ml. Secondary and tertiary amines do not interfere with theestimation. Two of the primary amines, diethylenetriamine and triethylenetetramine, interfere with the estimation when present in quantities of more than 10 μg per ml of the sample solutions. 1,3-Propanediamine interferes seriously. The colored compound was found to be composed of ethylenediamine, phthalaldehyde, and 2-mercaptoethanol in a molar ratio of 1:2:1.
An Improved Ion-exchanger Colorimetry for the Determination of a Trace Amount of Phosphate
Authors: Matsuhisa Kiichi , Ohzeki Kunio , Kambara Tomihito
Published: July 2006

A highly sensitive and selective method has been developed for the determination of a trace amount of phosphate. It is based on the concentration of phosphate as the familiar molybdenum blue complex on the coagulated material prepared from finely divided anion and cation exchangers, collection of the mixed resin on a filter paper, and the subsequent measurement of the absorbance of the complex on the resulting thin layer of resin phase. The calibration curve shows a good proportionality in the concentration range of 1 to 6 μg P1−1. The absorbance corresponding to 1 μg P1−1 is 0.095. The method is successfully applied to the determination of phosphate in a tap water and a river water.
Preparation and Electronic Spectra of Dichlorobis(1,10-phenanthroline)molybdenum(III) and Dichlorobis(2,2′-bipyridine)molybdenum(III) Ions
Authors: Morita Tomoji S , Sasaki Yoichi , Saito Kazuo
Published: July 2006

A preparation method of pure crystalline salts, cis-[MoCl2(phen)2]X (phen, 1,10-phenanthroline; X−=Cl−, Br−, CH3C6H4SO3−) and cis-[MoCl2(bpy)2]Cl (bpy, 2,2′-bipyridine), has been established. They are stable in solid state under oxygen- and moisture-free conditions. They deteriorate within one hour in water at room temperature, but are much more stable in various organic solvents free from oxygen. In the visible region, two absorption peaks were observed in methanol at 21510 cm−1 (ε=2570 dm3 mol−1 cm−1) and 26740 cm−1 (ε=4420 dm3 mol−1 cm−1) for the phen complex, and one broad peak at 22820 cm−1 (ε=3630 dm3 mol−1 cm−1) for the bpy complex, which are assigned to the metal-to-ligand d-π* charge transfer transition.
Isomers of Tris[(R)-1-phenyl-1,2-ethanediamine]- and Tris[(S)-3,3-dimethyl-1,2-butanediamine]cobalt(III), and the Related Complexes
Authors: Kojima Masaaki , Fujita Junnosuke
Published: July 2006

The [Co{(R)-1-phenyl-1,2-ethanediamine}3]3+ complex yielded all of the four possible isomers, mer-Δ(lel3), mer-Λ(ob3), fac-Δ(lel3), and fac-Λ(ob3), while the [Co{(S)-3,3-dimethyl-1,2-butanediamine}3]3+ complex gave only two isomers of merΛ-(lel3) and fac-Λ(lel3). Two isomers, Λ(lel3) and Δ(ob3) of the [Co{(S,S)-2,3-butane-diamine}3]3+ complex were obtained. The formation ratios of these tris(1,2-diamine)cobalt(III) complexes were compared with those of the analogous complexes and discussed. The tetraammine complexes of all those diamines were also prepared. Absorption and circular dichroism spectra of all the complexes were recorded.
A Novel Ring-closure Reaction between 1,4-Dihydroxyanthraquinone and Diamines Promoted by Copper Ions
Authors: Takei Toshio , Matsuoka Masaru , Kitao Teijiro
Published: July 2006

The reaction of 1,4-dihydroxyanthraquinone(DHAQ, 1) with various diamines were carried out in the presence of CuCl2. Primary 1,2-ethylenediamines or 1,2-cyclohexanediamine afforded the ring-closure products, 6-hydroxy-1,2,3,4-tetrahydronaphtho[2,3-f]quinoxaline-7,12-dione derivatives, in good yields of 70–98%. On the other hand, in the cases of N-alkylethylenediamines or 2-(alkylamino)ethanols, the major products were the 2-aminated 1,4-dihydroxyanthraquinones. The direct 2-amination of 1 was greatly inhibited when an alkyl group was introduced to the amino group because of its steric requirement. The role of copper ions, the effect of a steric requirement of the N-alkyl substituent of amines, and the effect of the chain length of alkanediamines in the reaction of 1 with amines were studied. It was proposed that the reaction was initiated by the direct 2-amination of 1  via the copper complex, followed by the intramolecular nucleophilic substitution of the 2-amino group on the 2-alkylamino substituent to give the ring-closure product.
Aldol Reaction of Aluminium Enolate Resulting from 1,4-Addition of R2AlX to α,β-Unsaturated Carbonyl Compound. A 1-Acylethenyl Anion Equivalent
Authors: Itoh Akira , Ozawa Shuji , Oshima Koichiro , Nozaki Hitosi
Published: July 2006

Organoaluminium reagents R2AlX (X=SPh, SeMe) easily add to α,β-unsaturated carbonyl compounds in 1,4-fashion. The resulting aluminium enolates react with aldehydes to give aldol adducts in fair to good yields. Formal elimination of HX from the adducts provides α-substituted α,β-unsaturated carbonyl compounds. The overall transformation is an addition of aldehydes to 1-acylethenyl anion equivalent. Diethylaluminium iodide also is found to be an efficient reagent for the same type transformation.
5-Amino-1-vinyl-4,5-dihydro-1H-1,2,3-triazoles as a Source of 1-Amino-2-aza-1,3-butadiene
Authors: Nomura Yujiro , Takeuchi Yoshito , Tomoda Shuji , Ito Masato M
Published: July 2006

Thermolysis of 4,4-dimethyl-1-(1-phenylvinyl)-5-(1-pyrrolidinyl)-4,5-dihydro-1H-1,2,3-triazole gave 2-methyl-N-(1-phenylvinyl)-1-(l-pyrrolidinyl)-1-propanimine, which reacted as a 2-azabutadiene with electrondeficient dienophiles to afford the corresponding [4+2] cycloadducts. Reactivity and regioselectivity of the cycloaddition reactions were rationalized with the frontier molecular orbital treatment.
Electronic Properties and π-π* Absorption Spectrum of 2-Pyridone
Authors: Fujimoto Akira , Inuzuka Kozo , Shiba Ryuichi
Published: July 2006

The IR and U V absorption spectra as well as the Raman spectra of monomer and dimer of 2-pyridone were studied. The molecular weight of 2-pyridone in benzene and dimethyl sulfoxide was determined in order to examine the association. 2-Pyridone in nonpolar solvents shows two types of carbonyl stretching vibration bands due to the coexistence of the monomer and dimer. The highest wavelength UV absorption of 2-pyridone in isooctane (2,2,4-trimethylpentane) is ascribed to π-π* electronic transitions of the monomer and dimer. The dimer absorption band appears at a higher wavenumber than that of the monomer by ca. 830 cm−1. The dimer band corresponds to the π-π* transition from the ground 1Ag state to the excited 1Bu state. No π-π* transition absorption from the ground 1Ag state to the excited 1Ag state could be observed because of the g-g Laporte forbiddance in the transition under an assumption of the molecular C2h symmetry.
Photochemical Isomerization of 6,7-Dicyano- and 6,7-Bis(methoxycarbonyl)-3-phenylsulfonyl-(2,4-exo)-3-azatricyclo[3.2.1.02,4]oct-6-ene
Authors: Umano Katsumi , Koura Hiroto , Inoue Hiroo
Published: July 2006

The photochemical reactions of 6,7-bis(methoxycarbonyl)- and 6,7-dicyano-3-phenylsulfonyl-(2,4-exo)-3-azatricyclo[3.2.1.02,4]oct-6-ene afford the corresponding tetracyclic compounds (3b and 3c) by the skeletal isomerization, but those of their endo isomers do not result in the formation of 3b and 3c.
Synthesis of 2-Substituted 1,3-Butadienes by Cross-coupling Reaction of 2-(1,3-Butadienyl)magnesium Chloride with Alkyl or Aryl Iodides
Authors: Nunomoto Sadaaki , Kawakami Yuhsuke , Yamashita Yuya
Published: July 2006

The cross-coupling reactions of 2-(1,3-butadienyl)magnesium chloride (1) with aryl and alkyl iodides were investigated in the presence of transition metal catalysts. Tetrakis(triphenylphosphine)palladium(0) catalyzes the cross-coupling reactions of 1 with aryl iodides, and copper (I) iodide catalyzes the reaction with alkyl iodides. These cross-coupling reactions offer convenient routes for the synthesis of 2-substituted 1,3-butadienes.
A Simple Regioselective Partial Hydrolysis of Di-O-isopropylidene Monosaccharides with Copper(II) Ion
Authors: Iwata Masaaki , Ohrui Hiroshi
Published: July 2006

Copper(II) ion was found to be effective for regioselective removal of the 5,6-O-isopropylidene group of α-d-mannose and α-d-glucose derivatives in alcohols at ambient temperature.
The Synthesis of Phenyl Carboxylates from p-Bromophenol and Carboxylic Acids
Authors: Hashimoto Shizunobu , Furukawa Isao
Published: July 2006

The reaction of p-bromophenol with carboxylic acids in the presence of triphenylphosphine and triethylamine proceeded at a high temperature, with the elimination of hydrogen bromide, to give phenyl carboxylates and small amounts of p-bromophenyl carboxylates.
The Reaction of cyclo-Tetraphosphate with l-Valine
Authors: Tsuhako Mitsutomo , Fujita Naoko , Nakahama Akiko , Matsuo Tsuneo , Kobayashi Masamitsu , Ohashi Shigeru
Published: July 2006

cyclo-Tetraphosphate (P4m) reacted with l-valine at pH 12 to form a certain phosphorus-containing compound (Compound X). Compound X was obtained in amounts so small as about 3.2% at room temperature after 91 d and about 0.3% at 70 °C after 1 d. Based on the results of paper chromatography, anion-exchange chroma-tography, and IR spectroscopy, Compound X was proved to be the same orthophosphate derivative of valine, an anion of N-(1-carboxy-2-methylpropyl)phosphoramidic acid, as that formed by the reaction of cyclo-triphosphate (P3m) with l-valine. The mechanism of the reaction of P4m with l-valine was discussed.
Binuclear Metal Complexes. XL. Synthesis and Magnetic and Spectral Properties of Alkoxo-bridged Copper(II) Complexes with 2-(Alkylthio)ethanols
Authors: Mikuriya Masahiro , Okawa Hisashi , Kida Sigeo
Published: July 2006

Alkoxo-bridged copper(II) complexes with 2-(alkylthio)ethanols, Cu(RSCH2CH2O)X (R=CH3, C2H5, n-C3H7, i-C3H7, s-C4H9, t-C4H9; X=Br, Cl), have been prepared and characterized by elemental analyses, infrared and electronic spectra and magnetic susceptibilities (80–300 K). Based on the magnetic properties, these complexes were divided into three types, A, B, and C. Type A complexes show a strong antiferromagnetic interaction and exhibit a distinct absorption band characteristic of alkoxo-bridged structure in the 22–24×103 cm−1 region. Type B and C complexes follow the Curie-Weiss law. The former complexes show a ferromagnetic behavior, whereas the latter complexes show a weak antiferromagnetism. The results were compared with those of the complexes with 2-(dialkylamino)ethanols, Cu(R2NCH2CH2O)X.
The Preparation and Properties of Ethylenediamine(8-quinolinolato)cobalt(III) Complexes
Authors: Yamamoto Yoshihisa , Kataoka Reiko , Imahara Shinji , Amano Toshio
Published: July 2006

Bis(ethylenediamine)(8-quinolinolato)cobalt(III) chloride dihydrate and ethylenediaminebis(8-quinolinolato)cobalt(III) chloride dihydrate have been isolated and characterized. The 1H-NMR spectrum of the latter complex indicates that the two oxygen atoms of the coordinated 8-quinolinolato ligands are in the cis positions.
Binuclear Metal Complexes. XLI. Crystal Structure and Unusual Magnetic Property of Isothiocyanato{2-[2-(dimethylamino)ethylthio]ethanolato}copper(II)
Authors: Mikuriya Masahiro , Okawa Hisashi , Kida Sigeo
Published: July 2006

A binuclear copper(II) complex, isothiocyanato{2-[2-(dimethylamino)ethylthio]ethanolato}copper(II), (Cu(CH3-nso)NCS), was prepared and characterized by elemental analysis, infrared and electronic spectra, magnetic susceptibility (90–300 K), and single-crystal X-ray diffraction. The complex exhibits a band at 25×103 cm−1 characteristic of alkoxo-bridged structure. The temperature dependence of the magnetic susceptibility is unusual and shows a dramatic change in the temperature range 240–180 K. The magnetic data were fitted to the Bleaney-Browers equation separately in the two temperature ranges (−2J=535 cm−1 for 300≥T≥240 K; −2J=595 cm−1 for 170≥T≥90 K).
Crystal Structure and Absolute Configuration of d-Tartaric Acid-(+)500CD-Tris(2-aminoethanesulfenato)cobalt(III)–Water (1/1/1)
Authors: Kita Masakazu , Yamanari Kazuaki , Kitahama Katsuki , Shimura Yoichi
Published: July 2006

The crystal structure and absolute configuration of diastereomeric molecular compound, d-C4H6O6·(+)500CD[Co{S(O)CH2CH2NH2}3]·H2O, were determined by the X-ray diffraction method. The crystals are orthorhombic with space group P212121, Z=4, and a=13.034(4), b=13.559(6), and c=11.048(8) Å. The rifinement of 1724 reflections (Mo Kα radiation) led to R=0.068. The complex molecule has the configuration fac(S)-Λ-(δ,δ,δ)-(R, R, R). All amino groups and the sulfenato oxygen atoms form hydrogen bonds with d-tartaric acid and/or water molecules three-dimensionally, which is responsible for the formation of the novel diastereomeric molecular compound.
Cobalt(III) Complexes with Tripodlike Quadridentate Ligands. I. Circular Dichroism Spectra of Quasi-enantiomeric Geometrical Isomers of [Co(tripod)(chiral bidentate)]-type Complexes
Authors: Akamatsu Keiji , Komorita Takashi , Shimura Yoichi
Published: July 2006

Cobalt(III) complexes containing a tripodlike quadridentate ligand, tris(2-aminoethyl)amine or nitrilotriacetate, and a chiral bidentate, l-amino carboxylate or (R)-propylenediamine, are prepared and separated into their respective geometrical isomers. The two geometrical isomers have mutually quasi-enantiomeric configurations. Circular dichroism spectra in the d-d absorption band region are discussed in connection with this novel type of geometrical isomerism.
Aromatic Nucleophilic Substitution. XV. Stopped-flow Kinetics of the Formation and Decomposition of 1,3- and 1,1-Disubstituted Meisenheimer Complexes in the Reactions of 1-Dialkylamino-2,4-dinitronaphthalenes with Potassium Methoxide in Dimethyl Sulfoxide-Methanol
Authors: Sekiguchi Shizen , Takei Toshio , Matsui Kohji , Tone Noboru , Tomoto Noboru
Published: July 2006

The formation of 1,3-disubstituted anionic σ complexes, followed by 1,1-disubstituted ones was confirmed by means of absorption and NMR spectra in the reactions of 1-dialkylamino-2,4-dinitronaphthalenes with potassium methoxide in DMSO-CH3OH. The rates and activation parameters were determined by kinetic studies with use of stopped-flow and conventional spectrophotometers. The rate constants for the formation of 1,3-disubstituted one decreased in the order 1-dimethylamino->1-(N-methylbutyl)amino->1-piperidino->1-diethylamino-2,4-dinitronaphthalenes, those for its decomposition being comparable with each other. On the other hand, the rate constant for the formation of 1,1-disubstituted one decreased in the same order as above while that for its decomposition decreased in the order 1-dimethylamino->1-(N-methylbutyl)amino->1-diethylamino->1-piperidino-2,4-dinitronaphthalenes. The mechanism was discussed from activation parameters.
Amino Sugars. XXXII. Ammonolysis and Azidolysis of Benzyl 2,3-Anhydro-4-azido-4-deoxypentopyranosides
Authors: Hashimoto Hironobu , Araki Koichi , Yoshimura Juji
Published: July 2006

Ammonolysis and azidolysis of four benzyl 2,3-anhydro-4-azido-4-deoxypentopyranosides of α-d-lyxo, α-d-ribo, β-l-lyxo, and β-l-ribo configurations, were studied. Ratios of two ring-opening isomers and relative reaction rates were determined, factors controlling the direction of ring opening being discussed.
The Reaction of Alkyl 3-Alkoxy-2-bromopropanoate with Triethyl Phosphite
Authors: Okamoto Yoshiki , Tone Tsutomu , Sakurai Hiroshi
Published: July 2006

Alkyl 3-alkoxy-2-bromopropanoate reacted with triethyl phosphite to give alkyl 2,3-bis(diethoxyphosphinyl)propanoate as the major product.
Photo-induced Radical Rearrangements of Hypoiodite of N-Acetyljervine and the Related C-nor-D-Homosteroid in the Presence of Mercury(II) Oxide and Iodine
Authors: Suginome Hiroshi , Kato Kimitoshi , Masamune Tadashi
Published: July 2006

Irradiation of the hypoiodite of N-acetyljervine in benzene containing mercury(II) oxide and iodine gave a mixture of products. The major product was N-acetyl-11-oxojerva-5,12(13)-dien-3β-yl N-acetyl-A-homo-4-oxa-11-oxojerva-5,12(13)-dien-3α-yl ether (4) (25%). Four minor products, N-acetyl-2-iodo-11-oxo-A-nor-2,3-secojerva 5,12(13)-dien-3-yl formate, N-acetyl-3α,5-epoxy-6α-iodo-A-homo-4-oxa-5α-jerva-5,12(13)-dien-11-one, N-acetyl-4-oxajerva-5,12(13)-dien-11-one, and N-acetyl-4-oxa-A-homojerva-5,12(13)-diene-3,11-dione, were also isolated. Irradiation of the hypoiodite of 3β-hydroxy-17-ethyletiojerv-5-ene-11,20-dione also gave a dimer corresponding to 4. The formation of 4 as the major product contrasts with the result of the corresponding reaction of cholesterol.