bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Artificial Signal Transduction System. Control of Lactate Dehydrogenase Activity Performed by an Artificial Cell-surface Receptor
Authors: Kikuchi Jun-ichi , Ariga Katsuhiko , Miyazaki Tatsuo , Ikeda Kouki 
Published: May 2003

Abstract
A supramolecular bilayer assembly as an artificial signaling system was constituted in combination with a steroid cyclophane as an artificial receptor, an NADH-dependent lactate dehydrogenase as an effector, and a bilayer-forming peptide lipid. Signal transduction from the receptor to the effector was observed for the present hybrid system by employing two kinds of signaling species, 1-hydroxy-2-naphthaldehyde as an external signal and a Cu(II) ion as a signal transmitter.
The Enantioselective Chalcogeno-Baylis-Hillman Reaction Using a Chiral Hydroxy Chalcogenide-TiCl4 Complex
Authors: Kataoka Tadashi , Iwama Tetsuo , Tsujiyama Shin-ichiro , Kanematsu Kiyoko , Iwamura Tatsunori , Watanabe Shin-ichi 
Published: May 2003

Abstract
The enantioselective chalcogeno-Baylis-Hillman reaction was investigated by the use of chiral hydroxy chalcogenides in the presence of TiCl4 under atmospheric pressure. The best result was obtained with 10-methylthioisobornenol as a chiral hydroxy chalcogenide.
Catalytic Asymmetric Acylation of Racemic Secondary Alcohols with Benzoyl Chloride in the Presence of a Chiral Diamine
Authors: Sano Tomohumi , Imai Keisuke , Ohashi Kousaburo , Oriyama Takeshi 
Published: May 2003

Abstract
Nonenzymatic kinetic resolution of racemic secondary alcohols is an efficient synthetic method to obtain optically active compounds in organic chemistry. Catalytic asymmetric acylation of racemic secondary alcohols has been successfully performed with achiral benzoyl chloride in the presence of only 0.3 mol% of chiral diamine (3) derived from (S)-proline, combined with 0.5 equivalent of triethylamine. This asymmetric acylation of various racemic cyclic secondary alcohols, 5, 6, or 8 membered cycloalkanols (1a–1c), hydroxyesters (1d and 1e), and bromohydrins (1f and 1g) gave the corresponding optically active benzoates (84–97% ee) and unreacted alcohols (79–95% ee). Racemic acyclic secondary alcohols (1h–1j) were also acylated in moderate enantioselectivity.
Novel Dehydrative Glycosylation by Using Acid Anhydride and TMSClO4
Authors: Wakao Masahiro , Nakai Yoshihiko , Fukase Koichi , Kusumoto Shoichi 
Published: May 2003

Abstract
Novel dehydrative glycosylation with 1-hydroxy sugars as glycosyl donors was achieved. Combination of trifluoroacetic anhydride or trichloroacetic anhydride as dehydrating agents with TMSClO4 as a Lewis acid afforded desired glycosides in good yields. t-Butyldiphenylsilyl and trichloroethoxycarbonyl groups at the 6-position of donors enhance α-selectivity of the glycosylation.
Molecular Imprinting in Hydrogen Bonding Networks of Polyamide Nylon for Recongnition of Amino Acids
Authors: Reddy P Sreenivasulu , Kobayashi Takaomi , Fujii Nobuyuki 
Published: May 2003

Abstract
Molecularly imprinted Nylon-6 was prepared from the polymer solution of formic acid having l-glutamine template. The recognition of amino acids by l-glutamine imprinted-polymer was evaluated by binding experiments for l-glutamine and its analogues. It was revealed that the recognition was effective for l-glutamine by the imprinted polymer as compared with its racemate d-glutamine and l- or d-glutamic acid.
A Mercurated Azobenzene Complex for Photoswitching between trans and cis Forms
Authors: Barigelletti Francesco , Ghedini Mauro , Pucci Daniela , Deda Massimo La 
Published: May 2003

Abstract
A pro-mesogenic compound based on an ortho-mercurated derivative of the azobenzene chromophore undergoes reversible trans-cis photoisomerization. By exploiting the spectral features of the orthometalated cis and trans isomers it is possible to produce photostationary states containing 78 and 90% of trans (rod-like, bright yellow) and cis (bent, colourless) isomers, respectively, which may be the basis for an efficient all-optical control of ON/OFF liquid crystalline behaviour.
A Simple and Rapid Protocol for N-Methyl-α-Amino Acids
Authors: Reddy G Vidyasagar , Iyengar DS 
Published: May 2003

Abstract
A two step strategy for optically pure N-Protected-N-methyl-α-amino acids starting from N-protected-α-amino acids via reductive cleavage of oxazolidinones using NaCNBH3/TMSCl is described.
The First Unequivocal Observation of Dynamic Solvent Effects in the Thermal Geometrical Isomerization of 3,3′-Diethyloxadicarbocyanine Iodide (DODCI)
Authors: Kim Jong Chul , Ohga Yasushi , Asano Tsutomu 
Published: May 2003

Abstract
Pressure dependence of the rate of thermal geometrical isomerization of 3,3′-diethyloxadicarbocyanine iodide (DODCl) was studied in ethanol and in a highly viscous hydroxylic solvent, 2-methyl-2,4-pentanediol. The kinetic effects of pressure in the two solvents are qualitatively different and the results strongly suggest that the stochastic analysis of the kinetic results in 1-alkanols reported earlier needs to be renounced.
Hydrothermal Synthesis of Fe-montmorillonite in Si-Fe-Mg System
Authors: Nagase Takako , Iwasaki Takeshi , Ebina Takeo , Hayashi Hiromichi , Onodera Yoshio , Dutta Niranjan Chandra 
Published: May 2003

Abstract
Fe-montmorillonite (Na0.3Fe3+1.7Mg0.3Si4O10(OH)2·H2O) was synthesized hydrothermally for 24 hours at 100 and 200 °C. XRD analysis showed the synthesized material to be crystalline Fe-montmorillonite without impurities, with d001=11-14.3 Å and d06=1.52-1.53 Å, respectively. The particle size of the material was found to be &gt; 500 Å by TEM. The X-ray photoelectron binding energy of Fe indicated that iron is present in smectite as Fe3+.
Silver or Copper Triflate-Catalyzed Amination of Silyl Enol Ethers
Authors: Kobayashi Shu , Yamashita Yasuhiro , Ishitani Haruro 
Published: May 2003

Abstract
Amination of silyl enol ethers with azo diester compounds proceeded smoothly in the presence of a catalytic amount of AgOTf or Cu(OTf)2. Various types of silyl enol ethers reacted smoothly under these conditions and AgOTf gave better yields than Cu(OTf)2 in most cases.
UV-visible Slab Optical Waveguide Spectroscopy of Cytochrome c Adsorbed on a Liquid-Solid Interface
Authors: Kato Kenji , Takatsu Akiko , Matsuda Naoki 
Published: May 2003

Abstract
A slab optical waveguide spectroscopy (SOWG spectroscopy) was applied to the UV-visible absorption spectroscopy. The SOWG with quartz core layer and amorphous fluorocarbon polymer clad layer has good transparency in UV-visible light region. It was demonstrated that adsorption process on the SOWG surface of cytochrome c was successfully observed in situ.
Diethylaluminum Ethoxide Mediated Stereoselective Diels-Alder Reaction of α,β-unsaturated Ketones and Acetoxy-1,3-butadienes as Diene Components
Authors: Shibata Jun , Shiina Isamu , Mukaiyama Teruaki 
Published: May 2003

Abstract
Stereoselective Diels-Alder reaction between several α,β-unsaturated ketones and acetoxy-1,3-butadienes is effectively performed by the promotion of diethylaluminum ethoxide under mild conditions. This reaction is successfully applied to the synthesis of optically active bicyclo[6.4.0]dodecanone 9 which corresponds to the BC ring system of 10-deoxy taxane derivatives from the 8-membered ring enone 7 and diene 2.
Construction of the Tetranuclear Complex with Inter- and Intramolecular Stacking-Like Arrangement Composed of Planar Palladium(II) Units
Authors: Yamada Yasunori , Okamoto Ken-ichi 
Published: May 2003

Abstract
The reaction of a square-planar S-donating metalloligand [Pd(aet)2] (aet = 2-aminoethanethiolate) with [Pd(NO3)2(bpy)] (bpy = 2,2′-bipyridine) gave a new type of S-bridged tetranuclear complex [Pd4(aet)4(bpy)2]4+ (1), in which two {Pd(bpy)} moieties are aligned so as to overlap each other by bridging with two [Pd(aet)2] units.
Tetrathiafulvaleno-quinonemethides and -thioquinonemethides
Authors: lwamatsu Masaki , Kominami Tsuyoshi , Ueda Kazumasa , Sugimoto Toyonari , Fujita Hideo , Adachi Tomohiro 
Published: May 2003

Abstract
Novel donor/acceptor-type tetrathiafulvalenes, tetrathiafulvaleno-quinonemethide and -thioquinonemethide were synthesized, which are expected as new π donor molecules bearing d local spin, because they can capture several magnetic metal ions through binding with the carbonyl oxygen or thiocarbonyl sulfur atom.
Donor-Acceptor Type Superconductor, (BETS)2(Cl2TCNQ)
Authors: Kondo Ryusuke , Hasegawa Tatsuo , Mochida Tomoyuki , Kagoshima Seiichi , Iwasa Yoshihiro 
Published: May 2003

Abstract
It was found that (BETS)2(Cl2TCNQ) is an all-organic superconductor, where BETS is bis(ethylenedithio)tetraselenafulvaleneand Cl2TCNQ is 2,5-dichlorotetracyanoquinodimethane.The superconducting critical temperature was 1.3 K ± 0.3 K under pressure.
Immobilization of a C2-Symmetric ansa-Zirconocene Complex on Silica Surfaces Using a Si-Cl Anchor: Catalysts for Isospecific Propene Polymerization
Authors: Suzuki Noriyuki , Asami Hayato , Nakamura Takashi , Huhn Thomas , Fukuoka Atsushi , Ichikawa Masaru , Saburi Masahiko , Wakatsuki Yasuo 
Published: May 2003

Abstract
A C2-symmetric ansa-zirconocene complex which has a Si-Cl moiety on its bridge was immobilized on SiO2 by the reaction of the Si-Cl anchor with Si-OH on the solid surface. The prepared solid catalyst was found to be effective for isospecific propene polymerization. It exhibited higher productivity compared to a catalyst prepared using the zirconocene without a Si-Cl anchor. The effect of pretreatment of silica surfaces with Me3SiCl on catalyst performance is also described.
Polytopic Coreceptor from Conformationally Stabilized Calix[6]arene for Alkali Metal Ions
Authors: Zhou Jinwei , Kawanishi Yuji , Zhang Yan , Yuan Hushan , Huang Zhitang 
Published: May 2003

Abstract
1:4 and 1:3 complexes of a conformationally stabilized calix[6]arene with NaI and KI were detected by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) for the first time.
Polymerization of Alkyl Methacrylate Catalyzed by Hydridorhenium Complexes
Authors: Komiya Sanshiro , Chigira Tomoko , Suzuki Toru , Hirano Masafumi 
Published: May 2003

Abstract
Hydridorhenium complexes having dimethylphenylphosphine ligands such as ReH(N2)(PMe2Ph)4, ReH(C2H4)2(PMe2Ph)3, ReH(PMe2Ph)5, ReH3(PMe2Ph)4, ReH5(PMe2Ph)3 smoothly induce polymerization of alkyl methacrylate in halogenated solvents such as dichloromethane, dichloroethane, chloroform, carbon tetrachloride, and dibromomethane at 30 °C.
Photochemical Reduction of NADP+ by Zinc Protoporphyrin Reconstituted Myoglobin as a Simple Model of Photosystem I
Authors: Nishiyama Katsuhiko , Uchiyama Miho , Mie Yasuhiro , Taniguchi Isao 
Published: May 2003

Abstract
Photoinduced electron transfer between zinc protoporphyrin reconstituted myoglobin (Zn-Mb) and NADP+ functions as a model of photosystem I by forming NADPH. The reduction efficiency of NADP+ depended strongly on the solution pH, which was explained by the difference in the redox potential and/or the static interaction between Zn-Mb and a sacrificial donor triethanolamine (TEA).
Geminal Bond Participation in the Cope Rearrangements of Z- and E-Substituted 1,5-Hexadienes and in the Reverse Reactions
Authors: Ikeda Hirotaka , Naruse Yuji , Inagaki Satoshi 
Published: May 2003

Abstract
We analyzed the bond interactions at the transition state of the Cope rearrangement of 1,5-hexadiene to disclose the significant participation of the geminal σ bonds at the reacting centers. The electron-donating σ bonds at the Z-positions and the electron-accepting σ bonds at the E-positions in the 1-substituted 1,5-hexadienes were predicted from the geminal bond participation to enhance the reactivities. For the reverse reactions, the 3-substituted 1,5-hexadienes were similarly predicted to rearrange more readily into the 1-substituted ones with the electron-donating σ bonds at the Z-positions. The predictions were confirmed by the density functional theory calculations.
A Layer-by-Layer Deposition of Concanavalin A and Native Glucose Oxidase to Form Multilayer Thin Films for Biosensor Applications
Authors: Anzai Jun-ichi , Kobayashi Yuka , Hoshi Tomonori , Saiki Hidekazu 
Published: May 2003

Abstract
Glucose oxidase (GOx) can be assembled into multilayer thin films without any chemical modification, by an alternate deposition of Concanavalin A (Con A) and native GOx on the surface of electrode. The Con A/GOx multilayer film-modified platinum electrodes functioned as a glucose biosensor.
Compositional and Carbon Isotopic Behavior of C19 and C20 Isoprenoid Hydrocarbons Produced by Laboratory Heating of Phytol: A Study of Formation of Pristane and Phytane from Chlorophylls on Diagenesis
Authors: Ishiwatari Mariko , Yamada Keita , Ishiwatari Ryoshi 
Published: May 2003

Abstract
Carbon isotopic ratios (δ13C) of isoprenoid hydrocarbons (isops) produced by heating (300-350 °C) of phytol were measured for understanding diagenetic reaction of chlorophylls. C19 isop was isotopically lighter than the phytol at the early stage of the heating and lighter than C20 isop regardless of heating temperature and time. Difference in δ13C between C19 and C20 isops observed in this study was similar to that observed for some petroleum.
Synthesis of Pyrrole Derivatives by the Heck-Type Cyclization of γ,δ-Unsaturated Ketone O-Pentafluorobenzoyloximes
Authors: Tsutsui Hironori , Narasaka Koichi 
Published: May 2003

Abstract
Substituted pyrroles are synthesized from γ,δ-unsaturated ketone O-pentafluorobenzoyloximes by the intramolecular Heck-type amination of the olefinic moiety catalyzed by Pd(PPh3)4.
Enclathrated Solvent Effects on the Photochromic Process of N-Salicylideneaniline in the Crystal State
Authors: Kawato Toshio , Kanatomi Hajime , Amimoto Kiichi , Koyama Hiroyuki , Shigemizu Hideki 
Published: May 2003

Abstract
N-{3,5-bis(1-methyl-1-phenylethyl)salicylidene}-4-tritylaniline and its clathrate crystals with methanol and acetone were prepared. Solvent effects were observed on the solid-phase photoisomerization of the Schiff base.
Stereospecific Total Synthesis of Amberketal and a Homologue
Authors: Kongkathip Boonsong , Kongkathip Ngampong , Janthorn Sirinan , Virarangsiyakorn Duangmanee 
Published: May 2003

Abstract
Amberketal (1a) and acetal homologue (2a) have been synthesised from a commercially available methyl acetoacetate involving palladium catalysed cyclisation as a key step.
Intracellular Responses of Hybrid Liposomes against Leukemia Cells Related to Apoptosis with Antitumor Activity
Authors: Matsumoto Yoko , Kato Toshihiro , Kemura Yoshinori , Tsuchiya Makoto , Yamamoto Megumi , Ueoka Ryuichi 
Published: May 2003

Abstract
Intracellular responses of hybrid liposomes against leukemia cells related to apotosis were observed for the first time along with the highly inhibitory effects.
Synthesis, X-Ray Structures, and Magnetic Properties of [Cu2(piv)4(Et3N)2] and [Cu6(piv)6(EtO)6] (Hpiv = Pivalic Acid): Role of Base for Dinuclear Adduct and Oligonuclear Formation
Authors: Mikuriya Masahiro , Azuma Hiroshi , Nukada Ryoji , Handa Makoto 
Published: May 2003

Abstract
Copper(II) pivalate adduct with triethylamine, [Cu2(piv)4(Et3N)2] (Hpiv = pivalic acid), and cyclic hexanuclear copper(II) complex, [Cu6(piv)6(EtO)6], have been synthesized and characterized by X-ray crystallography and magnetic susceptibility measurement.
The Effect of Humic Substances on Pb(II) Adsorption on Vermiculite
Authors: Jelinek Ludek , Inoue Katsutoshi , Miyajima Tohru 
Published: May 2003

Abstract
Adsorption of lead ion from aqueous solutions containing humic substances on vermiculite was investigated. Humic substances exhibited a strong influence on lead adsorption on vermiculite. The adsorption of humic acids on vermiculite plays an important role in lead ion distribution between the clay mineral and aqueous solution. There are remarkable differences in adsorption behaviors of humic acid itself among the humic acids taken from different origins. Adsorption behaviors of lead from aqueous solution containing fulvic acids were found to be less dependent on their origins, which may be attributable to negligible adsorption of fulvic acids on vermiculite.
Absolute Quantum Yields and Lifetimes of Photosensitized Phosphorescence of Singlet Oxygen O2 (1Δg) in Air-Saturated Aqueous and Organic Solutions of Phenalenone
Authors: Shimizu Okiyasu , Watanabe Jun , Imakubo Keiichi , Naito Shizuo 
Published: May 2003

Abstract
The absolute quantum yield ΦP of singlet oxygen (1O2) phosphorescence sensitized by phenalenone (PH) was determined together with the lifetime τ in 19 different solvents, using the known ΦP = (1.38 ± 0.05) × 10−3 in CCl4 as a standard. Measurements of both ΦP and τ were performed by combined use of a pulsed laser and a photon-counter coupled with a near-IR-sensitive photomultiplier. The ΦP value in water was determined to be ΦP = (4.5 ± 0.2) × 10−8.
Synthesis of Novel Cyclodextrin Derivatives Having Oligosaccharide Cluster
Authors: Furuike Tetsuya , Aiba Seiichi 
Published: May 2003

Abstract
A simple and facile method for the synthesis of novel 6-persubstituted β-cyclodextrin derivatives having a sugar cluster through a spacer arm is described. The coupling reaction of per-6-iodo-β-CD with each derivative of d-galactose (Gal) or N-acetyl-d-glucosamine (GlcNAc) smoothly proceeded and gave the corresponding cyclodextrin derivatives having seven sugar residues in excellent yields.
Oligomerization of Aromatic Tertiary Amines
Authors: Sato Hisaya , Kanegae Aiko , Yamaguchi Ryoji , Ogino Kenji , Kurjata Jan 
Published: May 2003

Abstract
The oligomerization of some tertiary aromatic amines was studied using ferric chloride in a variety of solvent. The predominant dimer formation of triphenylamine (TPA) was observed in chloroform at 0 °C where concentration of TPA was 0.125 mmol/l and the molar ratio of ferric chloride to TPA was 4. Except for N-methyldiphenylamine, high molecular weight oligomers were formed in a variety of solvents.
Electrochemical Measurement of Dissolved Oxygen from Atmosphere under a Magnetic Field Gradient
Authors: Kishioka Shin-ya , Aogaki Ryoichi 
Published: May 2003

Abstract
Electrochemical measurement using a steady state voltametry with a microdisk electrode revealed the effect of magnetic field on the acceleration of the dissolution of the atmospheric oxygen molecule into water containing tetraethylammonium-perchlorate as a supporting electrolyte in the initial state.
Enhancement of Diastereomer Selectivity Using Highly-Oriented Polymer Stationary Phase
Authors: Ihara Hirotaka , Sagawa Takashi , Nakashima Ken-ichi , Mitsuishi Kayoko , Goto Yoshihiro , Chowdhury Jamil , Sakaki Shigeyoshi 
Published: May 2003

Abstract
Enantiomer separation has been often realized with reversed phase liquid chromatography using diastereomerizing reagents with simply-hydrophobized silica. The present study demonstrates that diastereomer selectivity can be enhanced through highly-oriented organic phase produced by achiral poly(octadecyl acrylate)-grafted on silica and a carbonyl-π interaction due to the acrylate moiety is effective as the driving force for the selectivity enhancement.
Photoinduced Color Change of Methylviologen in Polycyano-Polycadmate Host Clathrates
Authors: Yoshikawa Hirofumi , Nishikiori Shin-ichi 
Published: May 2003

Abstract
A series of polycyano-polycadmate host clathrates accommodating a methylviologen dication and an organic molecule has been prepared. Some of them showed a color change from white to blue under UV-VIS light, which comes from the reduction of the methylviologen dication to its monocation radical. This phenomenon depends on the species of the coexistent organic guest and the crystal structure of the clathrates.
Structural Requirements of Zinc Porphyrin Derivatives on the Complex-Forming with Light-Harvesting Polypeptides
Authors: Kashiwada Ayumi , Watanabe Hiroyuki , Mizuno Toshihisa , Iida Kouji , Miyatake Tomohiro , Tamiaki Hitoshi , Kobayashi Masami , Nango Mamoru 
Published: May 2003

Abstract
Zn-bacteriochlorins or Zn-mesoporphyrins were successfully assembled with light-harvesting (LH)-α and -β polypeptides separately isolated from photosynthetic bacteria in n-octyl-β-d-glucopyranoside (OG) micelle, depending on the structure of Zn-porphyrin derivatives and on temperature.
Photoswitching of Intramolecular Magnetic Interaction: A Diarylethene Photochromic Spin Coupler
Authors: Matsuda Kenji , Irie Masahiro 
Published: May 2003

Abstract
We have designed and synthesized 1,2-bis[6-(1-oxyl-3-oxide-4,4,5,5-tetramethylimidazolin-2-yl)-2-methylbenzo[b]thiophen-3-yl]hexafluorocyclopentene which shows photoswitching of intramolecular magnetic interaction by incorporating two nitronyl nitroxide into diarylethene photochromic spin coupler.
Synthesis and Crystal Structure of a Water-soluble, Anionic Octanuclear Silver(I) Cluster Formed by 2-Mercaptobenzoic Acid (H2mba); K12[Ag8(mba)10]·12H2O
Authors: Nomiya Kenji , Noguchi Ryusuke , Kato Chieko 
Published: May 2003

Abstract
We have prepared a novel water-soluble silver(I) complex showing effective antibacterial activities K12[Ag8(mba)10]·12H2O (1a, H2mba = 2-mercaptobenzoic acid) from the Ag2O : H2mba : KOH = 1 : 4 : 8 molar ratio reaction in aqueous media and determined its crystal structure. The X-ray crystallography revealed that 1a was a discrete, anionic octanuclear silver(I) cluster consisting of two butterfly-type Ag4S4 subunits bridged by two µ3-S atoms.
Atomic Force Microscopy of Photolysis of Azobisisobutyronitrile in the Solid State
Authors: Zeng Qingdao , Wang Chen , Bai Chunli 
Published: May 2003

Abstract
The formation of regular nanostructures by photolysis of azobisisobutyronitrile (AIBN) in the solid state is investigated using atomic force microscopy (AFM) and known crystal packing data. AFM reveals that the crystal face (001) of AIBN yields both craters and volcanoes. All the experimental results are correlated with the crystal structure. Molecular interpretation of the AFM features of AIBN is given.
Double Acylation of Alkenes with Acylchromates Promoted by Cationic Pd(II) Complex
Authors: Yamane Motoki , Ishibashi Yuichiro , Sakurai Hidehiro , Narasaka Koichi 
Published: May 2003

Abstract
Double acylation of alkenes such as norbornene and vinylsilane proceeds by the use of acylchromate complexes and a cationic Pd(II) complex. When two different acylchromates are added successively to a mixture of alkene and the Pd complex, unsymmetrical diketones are obtained almost selectively.
A New Mercurophilic Troponoid Tetrathiacyclophane; 2,6,8,12-Tetrathia-1(2,7),7(2,7)-ditropona-4(1,3),10(1,3)-dibenzenacyclododecaphane
Authors: Mori Akira , Kubo Kanji , Nishimura Tatsuya , Kato Nobuo , Takeshita Hitoshi 
Published: May 2003

Abstract
Condensation reaction of 2,7-dibromotropone with 1,3-bis(mercaptomethyl)benzene afforded 2:2- and 1:2-condensates. Their structures were determined to be new troponoid tetrathiacyclophanes by X-ray crystallographic analyses; 2:2-condensate had a 1,2-alternate conformation and was well-stacked through π-π interactions. 1:2-Condensate had approximately a cone conformation. 2:2-Condensate formed a complex with Hg(II) ion.
A Direct and Selective Syntheses of α,α-Dichloro- and α-Chloro-ethyl Ketones by the Reaction of Alkyl Carboxylates with 1,1-Dichloroethyllithium
Authors: Shiina Isamu , Imai Yumiko , Kagayama Akifumi , Mukaiyama Teruaki 
Published: May 2003

Abstract
1,1-Dichloroethyllithium (5), generated by treating 1,1-dichloroethane (4) with lithium diisopropylamide (LDA) or n-butyllithium, reacted with alkyl carboxylates to afford the corresponding α,α-dichloro- or α-monochloro-ethyl ketones selectively in good to high yields. According to the above alkylation method, synthetic intermediates of Taxol, optically active α,α-dichloroethyl polyoxyketone 2 and α-chloroethyl polyoxyketone 3, were respectively synthesized from optically active methyl polyoxycarboxylate 1 in good yields.