bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Characterization of trans-[CoCl2(N4x)]+ (N4x = 1,4,7,10-Tetraazacycloheptadecane, -cyclooctadecane, -cyclononadecane, -cycloicosane, -cyclohenicosane, and -cyclodocosane)
Authors: Tsuchimoto Masanobu , Fujita Junnosuke 
Published: July 2006

Abstract
New macrocyclic ligands, 1,4,7,10-tetraazacyclooctadecane (N411), -cyclononadecane (N412), -cycloicosane (N413), -cyclohenicosane (N414), and -cyclodocosane (N415), and the Co(III) complexes, trans-[CoCl2(N4x)]+ (x = 10−15) were prepared and characterized. While two isomers, one has an RSSR(SRRS) and the other an RSSS(SRRR) configuration for the four chiral nitrogen atoms, were obtained for the N4x (x = 12−15) complexes, only the RSSR(SRRS) isomer was isolated for the N410 and N411 complexes. The ligand field strength of N4x (Δ(N)) decreases largely from x = 6 to 9 or 10, and then shows an increasing tendency with the increasing ring members. The reduction potential for the Co(III)/Co(II) couple (E1⁄2) becomes less negative with the increasing ring members, and the ΔEp(= Epa − Epc) values are very large for the N48–N411 complexes. The variations of these observed values with the number of ring members indicate that medium-sized chelate rings are unstable compared with other sized ones.
Magnetic Properties of Oxygen Centered Trinuclear Ruthenium(III) and Rhodium(III) Complexes
Authors: Kobayashi Hanako , Uryû Norikiyo , Tokiwa Ayako , Yamaguchi Tadashi , Sasaki Yoichi , Ito Tasuku 
Published: July 2006

Abstract
The magnetic susceptibility and ESR of triangular trinuclear coordination compounds, [Ru3(μ3-O)(μ-CH3COO)6(py)3]+ and [Ru3(μ3-O)(μ-CH3COO)6(py)3]+ salts of powders, were measured in the region between liquid-He temperature and room temperature. Ru(III) ions are in the low spin state and Rh(III) ions are diamagnetic. The experimental results were analyzed using a localized model with antiferromagnetic exchange interactions, while taking the molecular orbital moment Zeeman effect into consideration. A weak magnetic interaction through the μ-CH3COO bridges is discussed. The averaged g-factor of the Ru salt was about 2.26, and the best-fit antiferromagnetic exchange interaction was about J = −69.5 cm−1.
The Biogenetic-Type Cyclization of the Unsaturated Monocyclic Alcohol with Formic Acid; Facile Synthesis of the Tricarbocyclic Alcohol, (+)-2-Epi-allo-cedrol
Authors: Naemura Koichiro , Hasegawa Tomoyuki , Miyabe Hajime , Chikamatsu Hiroaki 
Published: July 2006

Abstract
The biogenetic-type cyclization of (+)-(3S)-2-(3-hydroxy-3-methyl-4-pentenyl)-1-methyl-3-(1-methylethenyl)cyclopentene, prepared from d-limonene, with formic acid gave stereo and regiospecifically the formates of the tricyclic compounds of the allo-cedrol skeleton, hydrolysis of which gave the unsaturated alcohols, (+)-(1S,5R,7R,8S)-2,6,6,7-tetramethyltricyclo[5.2.2.01,5]undec-2-en-8-ol (27) and (+)-(1S,5R,7R,8R-2,6,6,7-tetramethyltricyclo[5.2.2.01,5]undec-2-en-8-ol. Hydrogenation of 27 gave (+)-(1R,2S,5R,7R,8S)-2,6,6,7-tetramethyltricyclo[5.2.2.01,5]undecan-8-ol, (+)-2-epi-allo-cedrol.
Behaviors of α-Fluorocarbenoids Derived from the Nucleophilic Desulfinylation of α-Chloro-α-fluoroalkyl Sulfoxides
Authors: Uno Hidemitsu , Sakamoto Katsuji , Semba Fumihiko , Suzuki Hitomi 
Published: July 2006

Abstract
2-Aryl-1-chloro-1-fluoroethyl sulfoxides underwent nucleophilic desulfinylation with PhMgBr to give (Z)-fluorostyrene derivatives in a very stereoselective manner (&gt; 33 : 1) via an α-fluorocarbene species. When treated with 3 equiv of PhLi in the presence of N,N,N′,N′-tetramethylethylenediamine, they similarly formed fluorostyrenes as a stereoisomeric mixture (E : Z = 2 : 1), but with 1 equiv of PhLi 2-aryl-1-chloro-1-fluoroethanes were the major product. On the other hand, no formation of a fluoroalkene was observed in the desulfinylation of 1-chloro-1-fluoro-4-phenylbutyl sulfoxide with the nucleophiles. In the latter reaction, oxidation and/or phenylation of the intermediate carbene were the main pathways.
Nucleophilic Desulfinylation of α-Fluoro-β-(alkoxy and silyloxy) Sulfoxides.Effects of the β-Oxy Substituents on Protonation, 1,2-Hydrogen Migration, and Nucleophile Addition to the Fluorocarbenoid Centers
Authors: Uno Hidemitsu , Sakamoto Katsuji , Suzuki Hitomi 
Published: July 2006

Abstract
Treatment of 2-(4-biphenylyl)-2-t-butyldimethylsilyloxy-1-chloro-1-fluoroethyl phenyl sulfoxide with PhMgBr resulted in the formation of a fluorostilbene derivative, a fluoro enol silyl ether and small amounts of 4-(fluoroacetyl)biphenyl, while a similar reaction of 2-methoxymethoxy analog mainly led to the fluorostilbene derivatives and a simple desulfinylation product. In contrast, both sulfoxides reacted with PhLi to give chlorofluoro compounds and fluoro enol ethers. In these reactions, the stability of carbenoids derived from the nucleophilic removal of the sulfoxide moiety was greatly affected by the β-substituents, thus controlling the product distributions.
Electrochemical Investigations of High-Spin (10,20-Diaryletioporphyrinato II) Iron(III) Complexes
Authors: Kijima Masashi , Akimoto Kei , Sakawaki Akira , Sato Takeo 
Published: July 2006

Abstract
The redox behaviors of high-spin (10,20-diaryletioporphyrinato II) iron(III) complexes were investigated by cyclic voltammetry in both anodic and cathodic regions in dichloromethane. Whether the redox waves are due to a porphyrin-ring-centered reaction or a metal-centered reaction was examined in terms of the spectroelectrochemical results and Hammett reaction constants.
One-Color and Two-Color Resonance-Enhanced Two-Photon Ionization Studies of Benzene: Sudden Drop of Photoionization Yield at the Onset of the Third Channel Region
Authors: Ichimura Teijiro , Shinohara Hisanori , Ohashi Kazuhiko , Nishi Nobuyuki 
Published: July 2006

Abstract
Benzene molecules in a supersonic jet were photoionized using a tunable (233–262 nm) pulsed dye laser, and the resonance-enhanced two-photons ionization (RE2PI) processes of the S1 state were investigated by time-of flight (TOF) mass-spectrometric technique. Without further fragmentation of C6H6+ ions under low laser power conditions (&lt; 20 μJ/pulse), high-resolution excitation spectra of the parent ion have been measured for the 611n progression (n = 0,1,2,3). The relative photoionization intensity suddenly drops at the onset of the third channel band, 6113. Excitations of the rotationally resolved 6113 and 6112 bands under carefully controlled low laser powers have revealed the fact that the relative intensity of the 6113 band (above 3rd channel) to that of the 6112 band (below 3rd channel) decreases with decreasing the excitation laser power. This has confirmed the idea that the ionizing process is competing with nonradiative relaxation processes at the resonant state. Two-color RE2PI excitation with the pumping (ω1) and electrically delayed probing (ω2 = 272.0 nm) lasers has given population decay rates of vibronic state longer than 20 ns. Excitation spectra of the parent ion with scanning ω1 (241–248 nm) and those with the optically delayed (2.8–8.0 ns) fixed wavelength of ω2 have been observed. Relative population yields for the 71 and 6113 vibronic states drastically decreased in a similar fashion to the relative fluorescence yield for the longer delayed excitation. The present RE2PI measurement of the relative population yields for selective vibronic band excitations revealed that the ionization method can detect the non-fluorescent transient species produced the optical excitation above the 3rd channel of the S1 state of benzene.
Preparation of Bis(phthalocyaninato)lutetium with Various Substituents and Their Electrochemical Properties
Authors: Liu Yunqi , Shigehara Kiyotaka , Yamada Akira 
Published: July 2006

Abstract
A series of bis(phthalocyaninato)lutetium complexes with substituents on each benzoring [Lu(pc2R8)] was prepared and the electrochromic behavior investigated by means of cyclic voltammetry of coated electrodes.
Although the unsubstituted complex, Lu(pc)2, showed multistep electrochromism, its stability was quite unsatisfactory due to a falling-off of films from the electrode surface upon repetitive potential scanning. In the case of R = t-butyl, the improved solubility in organic solvents brought about an easier filming process and better adhesion to the electrode surface, though its high oxidation potential caused a cleavage of bi-peripheral complex. In contrast, complexes with electron-donating groups, such as R = propoxy or neopentyloxy, showed a lower oxidation potential and better stability upon repetitive potential scans, though the oxidized color was brownish rather than bright red. Complexes with 4 groups each of tetra-t-butyl and tetra propoxy had the oxidation potential close to that of octapropoxy or octakis(neopentyloxy) complexes and showed much improved stability and electrochromic behavior.
Reduction of Dicarboxylic Acid Anhydride with 2-Propanol over Hydrous Zirconium Oxide
Authors: Takahashi Kyoko , Shibagaki Makoto , Matsushita Hajime 
Published: July 2006

Abstract
The reduction of dicarboxylic acid anhydrides with 2-propanol proceeded efficiently over hydrous zirconium oxide to give the corresponding lactones and cyclic ethers. Secondary and primary alcohols, with the exception of methanol, are able to act as hydride donors in this reduction. The reduction proceeded as nearly second order concerning the concentration of 2-propanol and minus order concerning that of acid anhydride. These results suggest that the reduction was preferred under lower concentrations of acid anhydride and higher concentrations of 2-propanol. The selectivity of lactone or ether could be changed by the reaction temperature or the molar ratio of dicarboxylic acid anhydride to alcohol.
Optical Resolution by Replacing Crystallization of (RS)-4-Thiazolidinecarboxylic Acid with l-Amino Acids as Cosolute
Authors: Shiraiwa Tadashi , Yamauchi Masahiro , Tatsumi Takeshi , Kurokawa Hidemoto 
Published: July 2006

Abstract
The optical resolution by replacing crystallization of (RS)-4-thiazolidinecarboxylic acid [(RS)-THC] was carried out with coexisting eight l-amino acids and the effect of the latter was examined. l-Isoleucine [l-Ile] and l-cysteine [l-Cys] as the cosolute led to preferential crystallization of (R)-THC from an aqueous solution of (RS)-THC, whereas the other l-amino acids gave (S)-THC. l-Cys, l-threonine, l-4-hydroxyproline [l-Hyp], and l-serine as the cosolute seemed to give better selectivity for crystallization of one enantiomer than l-Ile, l-valine, l-proline, and l-alanine. The optical resolution with l-Hyp was successfully achieved and suggested a possibility of successive optical resolution to give both (R)- and (S)-THC.
Aromatization of Ethylene and C4 Hydrocarbons Using a Thermal Diffusion Column
Authors: Takagi Yuzuru , Aoyagi Toshiaki , Yoshida Takeo , Yada Satoru , Yamaguchi Tatsuaki , Esumi Yasuaki , Tanaka Kazunori 
Published: July 2006

Abstract
Thermal diffusion columns, consisting of water-cooled glass tubes and a coaxial red-hot metal wire, were applied as the reactor to dehydrogenative coupling of ethylene or C4 hydrocarbons. This application was intended to separate hydrogen spontaneously from other products, especially from aromatics, leading to enhanced yields. Hydrogen gas would ascend the red-hot wire, while the aromatics would descend the cold glass walls. When the metal wire was actually red-hot in the reactant hydrocarbon flow, oily products were really formed, most of which were mono- and bicyclic aromatic compounds such as benzene, styrene, and naphthalene. Product distributions were measured for different reactant species, wire metals, wire temperatures, and a few additional variables. Especially notable was the selective formation of 4-vinyl-1-cyclohexene from 1,3-butadiene at relatively low temperatures near 600 °C.
The Raman Active Intra- and Intermolecular Vibrations of [1H10]- and [2H10]p-Xylenes
Authors: Nakamura Seijiro , Sonoda Yoshitaka , Tominari Shigenori , Nibu Yoshinori , Shimada Hiroko , Shimada Ryoichi 
Published: July 2006

Abstract
Assignment of the Raman active normal vibrations of [1H10]- and [2H10]p-xylenes was made through the vibrational analysis of the polarized Raman spectra. Assignment of the low-frequency Raman bands to the rotational intermolecular vibrations of the crystals was also discussed.
Cobalt(III) Complexes with Quadridentate Ligands. XI.The Preparation and Properties of cis-α-Isomer of the Salicylato(triethylenetetramine)cobalt(III) Complex
Authors: Yamamoto Yoshihisa , Toyota Eiko , Kumon Toyo , Sekizaki Haruo 
Published: July 2006

Abstract
cis-α-Salicylato(triethylenetetramine)cobalt(III) chloride, cis-α-[Co(sal)trien]Cl, has been isolated and characterized by means of both analytical and spectroscopic methods.
Micellar Effect on the Formation Rate of Ni(II) and Co(II) Complexes with 8-Quinolinol and Its 5-Alkyloxymethyl-8-quinolinol Derivatives in a Nonionic Surfactant Micellar System
Authors: Tagashira Shoji , Onoue Kouichi , Murakami Yoshiko , Sasaki Yoshiaki 
Published: July 2006

Abstract
In the Triton X-100 micellar system, ligands such as 8-quinolinol and 5-alkyloxymethyl-8-quinolinol were distributed between the aqueous and micellar phases. The Ni(II) and Co(II) complexes were formed in both phases and their reaction rate constants in the aqueous phase were 2.8 × 103 and 1.3 × 105 mol−1 dm3 s−1, respectively. The reaction rates in the micellar phase were about one-tenth those in the aqueous phase. The distribution of ligand into the micellar phase delayed the observed reaction rate.
Selective Separation of Yttrium Ions from Other Rare Earth Ions Using Nonequilibrium Extraction
Authors: Minagawa Yukinori , Yajima Fumikazu 
Published: July 2006

Abstract
An advanced new method for the separation of yttrium ions from other rare earth ions using nonequilibrium extraction in the DTPA–B2EHPA system has been demonstrated. The extraction stages for obtaining yttrium oxide of 99.9% purity from yttrium oxide of 60% purity as a starting material were estimated to be about fifteen, which was the smallest value ever obtained, compared with the usual method (50–100 stages). The mechanism of the extraction reaction is discussed.
Stereoselectivities in Catalytic Hydrogenation of Several Branched-Chain 6-Deoxyhex-5-enopyranosides.A Synthesis of Branched-Chain Methyl 6-Deoxy-β-l-hexopyranoside
Authors: Sato Ken-ichi , Sakuma Shogo , Takahashi Kazuo , Hashimoto Hironobu 
Published: July 2006

Abstract
Hydrogenation of several 2-C, 3-C, and 4-C-methyl-branched 6-deoxyhex-5-enopyranosides in the presence of palladium–carbon in ethanol showed stereoselective formation of the corresponding 6-deoxy-β-l-hexopyranosides.
Reactions of 3-Isopropenyl- and 3-Acetyltropolone with Quarternary Ammonium Tribromides
Authors: Matsunaga Yoichiro , Imafuku Kimiaki 
Published: July 2006

Abstract
Treatments of 3-isopropenyltropolone with quarternary ammonium tribromides in tetrahydrofuran afforded 3-methyl-8H-cyclohepta[b]furan-8-one. The reactions in methanol–dichloromethane gave 7-bromo-3-methyl-8H-cyclohepta[b]furan-8-one. Bromination of 3-acetyltropolone with the tribromides in tetrahydrofuran produced 3-(bromoacetyl)tropolone, while the reaction in the methanolic solvent gave 7-bromo- and 5,7-dibromo-substituted 3-acetyltropolones. The brominations of 4′-hydroxyacetophenone were also carried out.
1,2-Addition of Allyl and 2-Oxo-2H-pyran-6-ylcarbonyl Groups to Cyclic C=N Double Bonds by Means of Organotin Reagent for Alkaloids Synthesis; A Facile Synthesis of 8-Oxoprotoberberine and Norketoyobirine (Demethoxycarbonyloxogambirtannine)
Authors: Yamaguchi Ryohei , Otsuji Atsuo , Utimoto Kiitiro , Kozima Sinpei 
Published: July 2006

Abstract
1,2-Introduction of allyl and 2-oxo-2H-pyran-6-ylcarbonyl groups into isoquinoline system can be effectively accomplished by reaction of allyltributyltin with 3,4-dihydroisoquinoline activated by 2-oxo-2H-pyran-6-ylcarbonyl chloride. Allyltributyltin reacts similarly with 3,4-dihydro-β-carboline activated by 2-oxo-2H-pyran-6-ylcarbonyl chloride to gave the corresponding 1,2-adduct. Intramolecular Diels–Alder reactions of the 1,2-adducts followed by DDQ oxidations afford 8-oxoprotoberberine and norketoyobirine.
2,3-Dichloro-5,6-dicyano-p-benzoquinone as a Mild and Efficient Catalyst for the Tetrahydropyranylation of Alcohols
Authors: Tanemura Kiyoshi , Horaguchi Takaaki , Suzuki Tsuneo 
Published: July 2006

Abstract
Hydroxy compounds readily add to 3,4-dihydro-2H-pyran under neutral conditions in the presence of a catalytic amount of 2,3-dichloro-5,6-dicyano-p-benzoquinone, to give high yields of the corresponding tetrahydropyranyl ethers.
Direct Iodination of Aromatic Compounds with Iodine and Alumina-Supported Copper(II) Chloride or Sulfate
Authors: Kodomari Mitsuo , Amanokura Natsuki , Takeuchi Kiyoshi , Yoshitomi Suehiko 
Published: July 2006

Abstract
The iodination of aromatic compounds (polymethylbenzenes, alkyl phenyl ethers, and polynuclear aromatic hydrocarbons) with iodine in combination with copper(II) chloride or sulfate supported on alumina proceeds well under mild conditions to selectively give monoiodinated compounds in high yields.
The Calculation of Temperature and Thermal Stress Distributions in the Planar Solid Oxide Fuel Cell
Authors: Kanamura Kiyoshi , Yoshioka Shoji , Takehara Zen-ichiro 
Published: July 2006

Abstract
The temperature and thermal stress distributions in a planar solid oxide fuel cell (SOFC) were calculated using a finite element method in order to determine guidelines for the selection of cell materials. The calculations indicate that the thermal stress is generated in a planar SOFC composed of yttria stabilized zirconia (YSZ) electrolyte, a LaMnO3 cathode, and a Ni-YSZ cermet anode. The largest stress is generated in the region of the cathode material. According to the calculations, if the linear expansion of the cathode material is 1.0 × 10−6 (the linear expansion of porous LaMnO3 is 2.0 × 10−5), the thermal stress in the SOFC will be relieved.
Determination of the Dimerization Constant in Self-Associating Systems
Authors: Hada Sakae , Neya Saburo , Funasaki Noriaki 
Published: July 2006

Abstract
The self-association of Methylene Blue (MB), a cholic acid derivative, chlorpromazine hydrochloride (CPZ), and octaethylene glycol decyl ether has been investigated by frontal gel filtration chromatography (GFC) and spectrophotometry at 25 °C. The stepwise aggregation constant ki is estimated as a function of aggregation number i from the centroid volume Vc of the GFC profile by using appropriate association models. The dimerization constants k2 for MB and CPZ determined by spectrophotometry are close to those from Vc values. The dimerization constants are also estimated from the concentration dependence of the peak volume Vp of the derivative GFC profile. The k2 values determined from the Vp values are slightly larger than those from the Vc values. This discrepancy is ascribed to the approximation of the Vp approach. The minimum multimerization concentration (mmc), above which multimers higher than trimer are formed, is determined from each of Vc, Vp, and absorption spectral measurements. The relation between mmc and the critical micelle concentration (cmc) depends on the degree of criticalness of cmc. This degree of criticalness increases as the aggregation number at the maximum ki value increases.
Kinetics and Mechanism of the High Temperature Selenidization of Cobalt
Authors: Takahashi Kazuhiro , Sasaki Yoshinori 
Published: July 2006

Abstract
A cobalt sheet was selenidized in selenium vapor of 1.33–13.33 kPa at 823–973 K by means of a sealed-tube method. X-Ray diffraction patterns and an electron probe microanalysis of the product films showed that double layers composed of thin outer CoSe2 and thick inner Co3Se4 were formed under all the reaction conditions employed. All the selenidizations obeyed a parabolic rate law and therefore the rate-determining step was apparently a diffusion process. The parabolic rate constant, Kp, was expressed as a function of the absolute temperature. The pressure dependence of Kp was not clearly recognized. A marker experiment indicated that cobalt was the component which diffused.
Binuclear Nickel(II) Complexes of Schiff Bases Derived from Salicylaldehydes and 1,n-Diamino-n′-hydroxyalkanes (n,n′ = 3,2; 4,2; and 5,3) Having an Endogenous Alkoxo Bridge and a Pyrazolato Exogenous Bridge
Authors: Mikuriya Masahiro , Sasaki Tomoko , Anjiki Atsushi , Ikenoue Shuichi , Tokii Tadashi 
Published: July 2006

Abstract
μ-Alkoxo-μ-pyrazolato-bridged binuclear nickel(II) complexes with 1,3-bis(salicylideneamino)-2-propanol (H3La), 1,4-bis(salicylideneamino)-2-butanol (H3Lb), and 1,5-bis(salicylideneamino)-3-pentanol (H3Lc), Ni2(La)(pz), Ni2(Lb)(pz), and Ni2(Lc)(pz) (pz = pyrazolate anion), have been prepared and characterized by elemental analyses, infrared and electronic spectra, and magnetic susceptibilities. The molecular structures of these complexes were determined by the single-crystal X-ray structure analyses. The planarities of the molecules were discussed in relation to the variation of the chain lengths of the Schiff bases.
Synthesis and Some Reactions of 2-Amino-1-azaazulene-3-carbaldehyde
Authors: Abe Noritaka , Tanaka Keiko , Yamagata Satoshi , Satoh Akira , Yamane Kameji 
Published: July 2006

Abstract
2-Chloro-1-azaazulene-3-carbaldehyde (1a) reacted with pyridine, followed by a reacion with piperidine to give 2-amino-1-azaazulene-3-carbaldehyde (1b) in excellent yield. Compound 1b was also obtained by a Vilsmeier–Haack reaction of 2-amino-1-azaazulene. Acetylation of 1b yielded a 2-acetylamino derivative, whereas methylation gave a 1-methylated compound. Reactions of 1b with hydrazines and alkylamines gave the corresponding hydrazones and Schiff bases, respectively, in excellent yields. The reactions of 1b with active methylene compounds gave 1,10-diazabenz[a]azulen-2(1H)-one derivatives. The reaction of 1b with guanidine gave pyrimidine-fuzed 1-azaazulene.
Photobromination of Side-Chain Methyl Groups on Arenes with N-Bromosuccinimide–Convenient and Selective Syntheses of Bis(bromomethyl)- and (Bromomethyl)methylarenes–
Authors: Futamura Shigeru , Zong Zhi-Min 
Published: July 2006

Abstract
Photobromination of side-chain methyl groups on arenes with N-bromosuccinimide (NBS) was investigated. Visible light irradiation in benzene solvent was extremely effective in increasing the selectivity of the reaction and the efficiency for product purification. The photobromination of 1,4-, 1,8-, 2,3-, and 2,6-dimethylnaphthalenes, 4,4′-dimethylbiphenyl, and p-xylene with 2.2 mol equivalents of NBS quantitatively afforded the corresponding bis(bromomethyl)arenes, respectively. The (bromomethyl)methylarenes were also obtained in good yields in the photobromination reactions of the above dimethylarenes with 1.1 mol equivalents of NBS.
Isomerization of Olefins by Means of R3SnH–Et3B and Stereochemical Study on Reduction of Alkenyl Iodides
Authors: Taniguchi Masahiko , Nozaki Kyoko , Miura Katsukiyo , Oshima Koichiro , Utimoto Kiitiro 
Published: July 2006

Abstract
Isomerization of olefins with R3SnH–Et3B (R = Ph or n-Bu) system has been studied. Treatment of (Z)-1-triphenylstannyl-1-octene (1) or (E)-1-triphenylstannyl-1-octene (2) with a catalytic amount of Ph3SnH–Et3B provided an equilibrium mixture of 1/2 = 2/8. Partial isomerization was observed in the reaction of trivial alkenes such as 6-dodecene and 2,2-dimethyl-3-dodecene with R3SnH–Et3B system. Whereas (Z)- or (E)-6-dodecene was recovered unchanged upon treatment with n-Bu3SnH–Et3B at −78 °C for 3 h, stirring a benzene solution of (Z)-6-dodecene, Ph3SnH, and Et3B at 60 °C for 5 h gave an isomeric mixture of (Z)-6-dodecene and (E)-6-dodecene (Z/E = 64/36). Taking account of these results, the stereochemistry of the reduction of alkenyl iodides at −78 °C with R3SnH–Et3B system was studied. 6-Dodecenyl radical proved to isomerize much more rapidly than it abstracts a hydrogen from R3SnH.