bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Highly Stereospecific Isomerization of Oxiranes into Allylic Alcohols by Means of Organoaluminum Amides
Authors: Yasuda Arata , Yamamoto Hisashi , Nozaki Hitosi 
Published: July 2006

Abstract
Organoaluminum reagents of type R1R2NAlR2 allow highly stereospecific oxirane ring opening producing allylic alcohols under mild conditions. trans-Epoxycyclododecane is converted to (E)-2-cyclododecen-1-ol by reaction with diethylaluminum 2,2,6,6-tetramethylpiperidide (DATMP) in quantitative yield, while the cis-isomer gives only 8% yield of the same alcohol. Furthermore, this reagent enables us to perform the stereospecific isomerization of trisubstituted oxiranes: c-3-butyl-2-methyl-r-2-pentyloxirane is transformed into 2-pentyl-1-hepten-3-ol and the diastereomeric oxirane into (E)-6-methyl-6-undecen-5-ol, respectively. Such a rigorous stereospecificity is rationalized on the basis of a concerted syn elimination via the boat-like six membered ring imtermediary stage, in which the substituents of the oxirane ring should be arranged so as to minimize the severe nonbonded interactions.
Alkylation and Acylation of Active Methylene Compounds Using 1,8-Diazabicyclo[5.4.0]undec-7-ene as a Base
Authors: Ono Noboru , Yoshimura Tetsuji , Saito Tadashi , Tamura Rui , Tanikaga Rikuhei , Kaji Aritsune 
Published: July 2006

Abstract
Active methylene compounds are selectively monoalkylated with alkyl halides in benzene using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as a base. Selectivity of monoalkylation decreases when the reaction is carried out in a polar solvent. Ethyl acetoacetate is O-acylated with acyl halides in the presence of DBU in acetonitrile to give the (E)-enol esters stereoselectively.
Temperature Effects on CD Spectra of β-Cyclodextrin Complexes with 2-Substituted Naphthalenes
Authors: Harata Kazuaki 
Published: July 2006

Abstract
CD spectra of β-cyclodextrin complexes with 2-naphthol, 2-naphthyloxyacetic acid, potassium 2-naphthoate, and potassium 2-naphthylacetate were measured at various concentrations of β-cyclodextrin and at temperatures ranging from 10 to 70°C. The temperature-dependent CD spectra of the 2-naphthyloxyacetic acid complex clearly show the 1 : 1 complex formation, but the other three complexes give CD intensity changes which are inexplicable in terms of the 1 : 1 stoichiometry. The molecular ellipticity and thermodynamic parameters were determined by the least-squares method. Enthalpy and entropy are in the ranges from −22.2 to −26.8 kJ·mol−1 and from −24 to −38 J·K−1·mol−1, respectively. They are strongly correlated to the volume of the substituent of the guest molecule, although the free energy is found in a quite narrow region (from −14.3 to −15.4 kJ·mol−1). The correlation is explained on the basis of the β-cyclodextrin-guest interaction and the solvation around the guest molecule.
A Simple Total Synthesis of (+)-Ferruginol, (+)-Sempervirol, and (+)-Podocarpa-8(14)-en-13-one
Authors: Matsumoto Takashi , Usui Shuji 
Published: July 2006

Abstract
The Wittig reaction of (R)-(−)-α-cyclocitral with (3-isopropyl-4-methoxybenzyl)-, (4-isopropyl-3-methoxybenzyl)-, and (3-methoxybenzyl) triphenylphosphonium chloride afforded the styryl derivatives which were partially hydrogenated to the corresponding dihydro derivatives (18, 26, and 27). Intramolecular cyclization of 18 and 26 with anhydrous aluminium chloride followed by demethylation with boron tribromide gave (+)-ferruginol and (+)-sempervirol. The similar cyclization of 27 gave (+)-13-methoxypodocarpa-8, 11, 13-triene. This was reduced with lithium in liquid ammonia in the presence of ethanol and then treated with dilute hydrochloric acid to give (+)-podocarpa-8(14)-en-13-one, a versatile intermediate for natural diterpene synthesis.
Radical-Ion Interaction. Diphenylmethyl and Triphenylmethyl Radicals Generated by the Dissociative Electron Attachment to Halogenated Compounds in Rigid Matrices
Authors: Izumida Tatsuo , Tanabe Yoshio , Ichikawa Tsuneki , Yoshida Hiroshi 
Published: July 2006

Abstract
Dissociative electron attachment to diphenylmethyl halides and triphenylmethyl halides in a γ-irradiated 3-methylhexane matrix at 77 K generates free radicals temporarily associated with a counterpart halide ion. The association is indicated by changes in the fluorescence and excitation spectra of the radicals as well as the charge-transfer excitation band of the radical-ion complexes.
Measurement and Analysis of the ν3 Band of CF4
Authors: Suzuki Tetsuo , Okada Hiroshi , Fujiyama Tsunetake 
Published: July 2006

Abstract
The ν3 fundamental of carbon tetrafluoride has been measured with a tunable diode laser-source spectrometer. The following molecular constants were obtained: ν0−2(Bζ3)eff=1283.4067 cm−1, BeffPR+B0−2(Bζ3)eff=7.210×10−2 cm−1, BeffPR–B0=−5.290×10−4 cm−1, and δ3=6.153×10−4 cm−1. Using the rg-structure obtained from the gas-electron diffraction study, the above molecular constants were reduced to be: ν0=1283.7181 cm−1, BeffPR=0.1915 cm−1, B0=0.1920 cm−1, and (Bζ3)eff=0.1557 cm−1. From the (Bζ3)eff value, the Coriolis coupling constant for the ν3 was estimated to be ζ3=0.811.
Asymmetric Cyclization of Propylene Chlorohydrins Catalyzed by an Optically Active Cobalt(salen) Type Complex
Authors: Takeichi Tsutomu , Ishimori Michihiro , Tsuruta Teiji 
Published: July 2006

Abstract
By using an optically active cobalt complex, N,N′-disalicylidene-(1R,2R)-1,2-cyclohexanediaminatocobalt(II), as a catalyst, optically active methyloxirane was synthesized by the asymmetric elimination of hydrogen chloride with a base from racemic propylene chlorohydrins. The highest optical purity of methyloxirane so far obtained was 35%, observed when 2-chloro-1-propanol and potassium carbonate were used as substrate and base, respectively. The optical rotations of the products and of the unchanged substrates indicate that (S)-1-chloro-2-propanol reacted selectively to produce (S)-methyloxirane, whereas in the case of 2-chloro-1-propanol, the (R)-isomer was preferentially cyclized to give (S)-methyloxirane with inversion of the asymmetric carbon. The physicochemical data of the circular dichroism and absorption spectra indicated a complexation of the optically active cobalt(II) species with potassium carbonate, either the (R)- or (S)-substrate interacting selectively with the Co*/K2CO3complex formed, followed by cyclization of the substrate.
A New Peptide Synthesis Using 2-Fluoro-1,3,5-trinitrobenzene. Syntheses of Thyrotropin Releasing Hormone and Leucine–Enkephalin
Authors: Kinoshita Hideki , Inomata Katsuhiko , Miyano Osamu , Kotake Hiroshi 
Published: July 2006

Abstract
2-Fluoro-1,3,5-trinitrobenzene has been found to be a useful new condensing reagent for peptide synthesis. A variety of dipeptides have been prepared from the corresponding amino acids with the reagent. The Young test under certain conditions did not cause racemization during the procedures. Subsequent application of this reagent enabled the syntheses of thyrotropin releasing hormone and leucine-enkephalin in good yields.
One-electron Reduction of 1-Benzyl-3-carbamoylpyridinium as a NAD+ Model
Authors: Ohnishi Yutaka , Kitami Miyoko 
Published: July 2006

Abstract
The pyridyl radical generated chemically or electrochemically by the le-reduction of 1-benzyl-3-carbamoylpyridinium undergoes dimerization to give mainly four dimers, diastereomers of 4,4′- and 4,6′-linked dimers. Isomerization between the dimers proceeds readily.
The Photo-Beckmann Rearrangement of A-Nor-5α-cholestan-3-one Oxime
Authors: Suginome Hiroshi , Takeda Hiroshi , Masamune Tadashi 
Published: July 2006

Abstract
The photo-Beckmann Rearrangement of A-nor-5α-cholestan-3-one oxime affords 4-aza-5α-cholestan-3-one and 3-aza-5α-cholestan-4-one as the only lactams.
Molecular Structure of Bromoform as Determined by a Joint Analysis of Electron Diffraction and Microwave Data
Authors: Tamagawa Koichi , Kimura Masao 
Published: July 2006

Abstract
The gas phase molecular structure of bromoform has been studied by electron diffraction. By a joint analysis of the diffraction results and the moments of inertia for CH79Br3, CD79Br3, CH81Br3, and CD81Br3 obtained by Williams et al., the bond distances in rg and the bond angles in \varphiav have been determined as follows: rg(C–Br)=1.924±0.005 Å, rg(Br…Br)=3.175±0.003 Å, rg(C–H)=1.111±0.046 Å, \varphiav(BrCBr)=111.7±0.4°, and \varphiav(HCBr)=107.2±0.5°. The uncertainties represent the estimated limits of error. The anharmonicity parameter of the Morse-type potential, a3, for the nonbonded Br…Br atom pair has been estimated as −1.3±0.9 Å−1.
Binding Forces Contributing to the Association of Cyclodextrin with Alcohol in an Aqueous Solution
Authors: Matsui Yoshihisa , Mochida Kazuo 
Published: July 2006

Abstract
The association constants and thermodynamic parameters were determined for complexes of α- and β-cyclodextrins (CD) with a variety of alcohols (ROH) by the spectrophotometric examination of the inhibitory effect of ROH on the association of CD with azo dyes, and they were analyzed in connection with the partition coefficients of ROH in a diethyl ether–water solvent system in order to elucidate the binding forces contributing to the association of CD with an organic substrate. Hydrophobic and van der Waals interactions were of primary importance in the complexation. Among them, the latter was preferential in α-CD–1-alkanol adducts, while the former, in β-CD–1-alkanol adducts. As the bulkiness of ROH increased, the stability of the α-CD adduct was lowered owing to van der Waals repulsion between ROH and the relatively small α-CD cavity, whereas that of the β-CD adduct was enhanced by the attainment of the close van der Waals contact of ROH with the relatively large β-CD cavity.
Magnetic Study of N,N,N′,N′-Tetramethyl-p-phenylenediamine (Wurster’s Blue) Tetrafluoroborate Cation Radical
Authors: Yamauchi Jun , Fujita Hideo , Deguchi Yasuo 
Published: July 2006

Abstract
Wurster’s Blue cation radical, which is composed of TMPD cation and BF4 anion moieties, was prepared and its magnetic properties were examined. The cation radical shows similar magnetic behavior to that of the TMPD–ClO4 cation radical, but there is a slight perturbation when changing the counteranions from perchlorate to tetrafluoroborate. A phase transition takes place at 190.5 K, which is attributable to a dimerization involving a small molecular displacement in the crystal lattice. These phenomena are discussed using the magnetic susceptibility data, thermal study, and ESR observations due to triplet exciton. The magnetic data are described by comparison with Wurster’s Blue perchlorate cation radical.
Enthalpies of Dilution of Aqueous Sodium Chondroitin 4-Sulfate and 6-Sulfate
Authors: Tsuge Hideya , Yonese Masakatsu , Kishimoto Hiroshi 
Published: July 2006

Abstract
Enthalpies of dilution of aqueous sodium chondroitin 4- and 6-sulfate were measured by a microcalorimeter from the various initial concentrations m=0.16–0.07 monomole kg−1 to the final concentration m′=3.85×10−3monomole kg−1 at various temperatures. The concentration and temperature dependencies of measured enthalpies well agreed quantitatively with the theoretical ones calculated by Manning’s limiting law, when the distance between the neighboring charges of polyion, b, was assumed to be 4.8 Å, which was obtained from X-ray diffraction measurement.
An Analysis of Impedance in the Kolbe Reaction on Platinum and Gold Anodes in Aqueous Acetate Solutions
Authors: Sekine Isao , Ohkawa Hideki 
Published: July 2006

Abstract
The Kolbe reaction occurring on platinum or gold anodes in aqueous acetate was studied by analyzing the equivalent circuit of the impedance obtained with a phase-sensitive detector. In the case of platinum, the equivalent circuit at the potential for the Kolbe reaction is represented by a parallel combination of the double-layer capacity, Cdl, and the charge-transfer resistance, θ, in series with the solution resistance, Rsol. The Cdl value of 2.00 V obtained by a complex impedance plane plot is nearly identical to that calculated by assuming that the Helmholtz layer is occupied by CH3COO−. In the potential range more negative than 2.00 V, the Kolbe reaction occurs. The steep decrease in the differential capacity is considered to be a result of the decrease in the adsorption pseudocapacity. The θ value of the oxygen evolution increases with an increase in the acetate concentrations. It is shown that the surface coverage of CH3COO− may be obtained by “Frumkin’s treatment” in conjunction with the high-frequency capacitance, CHF, and the low-frequency capacitance, CLF, from the complex capacitance plane plot (Y/ω plane plot). The Kolbe reaction does not occur at all with gold anodes, and the specific circular arc was not seen in the Y/ω plane plot. Impedance measurements, therefore, confirm that an adsorption pseudocapacity of CH3COO− is not present with gold anodes.
Reversible Binding of NO to Fe(II)edta
Authors: Hishinuma Yukio , Kaji Ryuichi , Akimoto Hidetoshi , Nakajima Fumito , Mori Toshikatsu , Kamo Tomoichi , Arikawa Yoshijiro , Nozawa Shigeru 
Published: July 2006

Abstract
The equilibrium constants, enthalpy, and entropy of the reversible binding of nitrogen oxide to Fe(II)edta in an aqueous solution have been measured in the temperature range 38.5 to 70 °C. Experiments were carried out by absorbing NO under O2 free conditions. The results show that, in the absorption of NO with Fe(II)edta solution, the value of ΔH° is −15.8 kcal/mol and ΔS° is −20.7 e.u.
An X-Ray Photoelectron Spectroscopic Study of 2-Mercaptobenzothiazole Metal Complexes
Authors: Yoshida Tooru , Yamasaki Kiyoshi , Sawada Shigemasa 
Published: July 2006

Abstract
The X-ray photoelectronic spectra of 2-mercaptobenzothiazole (LH) and its metal complexes have been measured. On the basis of the chemical shifts of the N(1s), S(2p), and Cu(2p3⁄2) electron binding energies, the coordination mode of the ligand and the oxidation state of the copper atom have been examined. It is suggested that, in HgL2, PbL2, AgL, and CuL3H2Cl complexes, the ligand is solely coordinated through the exocyclic sulfur atom, and that, in CuL, CuL2, PtL2, PdL2, NiL2, and CdL2 complexes, the ligand is coordinated through both the exocyclic sulfur and nitrogen atoms. In CuL2 and CuL3H2Cl, it was found that the copper was present in a (+1) oxidation state, and that part of the ligand molecules, bis(benzothiazol-2-yl) disulfide, resulted from oxidation of LH by the Cu2+ ion on complex formation.
The Synthesis of 5,2′-Dihydroxy-6,8-dimethoxyflavone and Its Isomers: A Revised Structure of Skullcapflavone I
Authors: Horie Tokunaru , Tsukayama Masao , Masumura Mitsuo , Nakayama Mitsuru , Hayashi Shûichi 
Published: July 2006

Abstract
5,2′-Dihydroxy-6,8-dimethoxyflavone, which had been proposed as the structure of skullcapflavone I isolated from Scutellaria baicalensis Georgi, was synthesized from 2-hydroxy-3,5,6-trimethoxyacetophenone. However, the synthetic flavone was not identical with the natural flavone. Thus, two isomeric flavones, 5,2′-dihydroxy-7,8-dimethoxyflavone and 5,2′-dihydroxy-6,7-dimethoxyflavone, were prepared from the corresponding acetophenones; the structure of skullcapflavone I was confirmed to be 5,2′-dihydroxy-7,8-dimethoxyflavone.
Reduction of Methylene Blue with l-Ascorbic Acid or l-Cysteine in Micellar Systems
Authors: Sen\={o} Manabu , Kousaka Kouichi , Kise Hideo 
Published: July 2006

Abstract
The reduction of Methylene Blue (MB) with l-ascorbic acid to the corresponding leuco compound has been studied in aqueous surfactant solutions. The reduction was accelerated in the presence of cationic surfactant hexadecyltrimethylammonium bromide, but tetrabutylammonium bromide, which has no ability of micelle formation, does not show any effects on the reaction rate. The micellar effects are largely affected by pH of the medium, and the rate enhancing effects of the micelles are retarded by KCl. These results could be interpreted by the change in dissociation state of the substrate on the micelle surface and by the binding of the reaction product, leuco MB, to the micelles. The binding site of leuco MB was found to be outer core of the HTAB micelle by NMR. Similar results were obtained in the reduction of MB with l-cysteine, although the reduction did not proceed without the addition of cationic surfactant. The interaction between dissolved oxygen and the substrate in HTAB micellar solutions was also investigated.
The Photochemical Dimerization of 2-Acyl-1,4-quinones
Authors: Miyagi Yo , Maruyama Kazuhiro , Ishii Hideo , Mizuno Sachie , Kakudo Masao , Tanaka Nobuo , Matsuura Yoshiki , Harada Shigeharu 
Published: July 2006

Abstract
2-Acyl-1,4-benzoquinones and 2-acyl-1,4-naphthoquinones underwent a novel type of regiospecific and stereospecific cyclodimerization by photolysis. The reaction was general, being not affected by any variation in the substituents and solvents. The structure of the dimers was elucidated as 4aα-acyl-10β-alkyl-5,8-dihydroxy-4aα,10aα-dihydro-1,4,9(10H)-phenanthrenetriones and dibenzo [b,h] homologues (8). The structure of 8 suggests that the dimerization proceeds through cis-ring fusion, disposing two substituents of the dimer (an acyl and an alkyl group) to a trans configuration.
Decomposition of Ozone on Natural Sand
Authors: Suzuki Shin , Hori Yoshio , Koga Osamu 
Published: July 2006

Abstract
Ozone decomposition on natural sand has been studied with a flow system. Ozone decomposed significantly on natural sand and in particular on iron sand. Silica, alumina, and iron oxides, the major components of the sand, were also capable of decomposing ozone.
Convenient Preparation of Furanoeremophilane and Menthofuran
Authors: Sato Toshichika , Tada Masahiro , Takahashi Takeyoshi 
Published: July 2006

Abstract
Pulegone was transformed into isopulegone enol acetate or isopulegone ethylene acetal, which was treated with m-chloroperbenzoic acid and then with acid to give menthofuran. Fukinone was converted into furanoeremophilane by the same procedure.
Theory of A.c. Polarization and A.c. Polarography and Voltammetry of Surface Redox Reaction
Authors: Kakutani Tadaaki , Senda Mitsugi 
Published: July 2006

Abstract
Theoretical equations are presented of the a.c. polarization and of the a.c. polarography and voltammetry for the surface redox reaction (Oad+ne\ightleftharpoonsRad) in which charge transfer reaction takes place exclusively between the adsorbed reactants Oad and Rad, and both reactants are adsorbed so strongly that the amount of O or R brought to or removed from the electrode surface can be neglected. The interaction between adsorbed molecules is assumed to be expressed by Frumkin’s a-parameters. Also the effect of the double layer impedance is taken into account. Some simplified cases are discussed in detail.
Crystal Structure and Related Physical Properties of [N,N,N,N′,N′,N′-Hexamethylhexamethylenediammonium]2+-[Tetracyanoquinodimethane]42−: as a Two-dimensional Magnetic System
Authors: Flandrois Serge , Chasseau Daniel , Delhaes Pierre , Gaultier Jacques , Amiell Jacques , Hauw Christian 
Published: July 2006

Abstract
The crystal structure, electrical conductivity and magnetic properties of (HMHDA)(TCNQ)4 are studied. It appears that this ion-radical salt consists of planar arrays of (TCNQ)2− dimers (diads) in weak interaction. The structure may thus be considered as quasi two-dimensional, the magnetic behavior being in line with two-dimensionality.
The Photochemical Reaction of Benzo[c]cinnoline. II. Photo-reduction in Acidic 2-Propanol
Authors: Inoue Hiroyasu , Hiroshima Yukimi , Makita Norio 
Published: July 2006

Abstract
The photochemical reduction of benzo[c]cinnoline in strongly acidic 2-propanol (4 M HCl) has been studied using light of wavelength longer than 400 nm. The photoproduct has been identified as 5,6-dihydrobenzo[c]cinnoline. The quantum yields for product formation, which are the same as that for the disappearance of the reactant, have been measured under various conditions. In contrast to the poor phosphorescent property of benzo[c]cinnoline, the protonated species has been found to phosphoresce with significant efficiency. The lowest triplet state energy has been estimated to be 51 kcal/mol. The results of the quenching showed that the photoreduction was attributed to the lowest excited triplet state of protonated benzo[c]cinnoline. The pKa value in the reactive state is lower than that in the ground state.
Conformational Transition of Poly(l-glutamic acid) in Aqueous Decylammonium Chloride Solution
Authors: Satake Iwao , Gondo Takeshi , Kimizuka Hideo 
Published: July 2006

Abstract
The cooperative binding of decylammonium chloride to poly(l-glutamic acid) (PLG) was studied by the potentiometric measurement of the binding isotherm at pH 7.9. Circular dichroism spectra were also measured as a function of the degree of binding of surfactant ion (x). It was shown that the coil to α-helix transition of PLG-surfactant complex takes place with a change in x. PLG did not undergo an appreciable conformational change in the range of x below 0.55. But the helical content increased suddenly with further increase in x. An abrupt increase in the helical content of PLG-surfactant complex can be well interpreted in terms of the hydrophobic interaction among bound surfactant ions. On the basis of the theoretical analysis of the cooperative binding isotherm, it was concluded that the formation of a micelle-like cluster consisting of at least eight surfactant ions is required for the stabilization of a surfactant induced helical structure.
Chemistry of N-Thiosulfinylanilines. IV. Reactions of N-Thiosulfinyl-anilines with Electrophilic Reagents
Authors: Inagaki Yoshio , Okazaki Renji , Inamoto Naoki 
Published: July 2006

Abstract
Reaction of 2,4-di-t-butyl-6-methyl-N-thiosulfinylaniline (1) with m-chloroperbenzoic acid (MCPBA) afforded the corresponding aniline and N-sulfinylaniline. Reaction of MCPBA with 2,4,6-tri-t-butyl-7,8-dithia-9-azabicyclo[4.3.0]nona-2,4,9-triene equilibrated with 2,4,6-tri-t-butyl-N-thiosulflnylaniline gave 2,4,r-6-tri-t-butyl-7,8-dithia-9-azabicyclo[4.3.0]nona-2,4,9-triene t-7-oxide (12), 4,6-di-t-butyl-3H-1,2,3-benzodithiazole 2-oxide (13), and 2,4,6-tri-t-butyl-N-sulfinylaniline (14). The oxide 13 was considered to be produced via a primary product 2,4,r-6-tri-t-butyl-7,8-dithia-9-azabicyclo[4.3.0]nona-2,4,9-triene t-8-oxide which was found to be unstable above −30 °C. Thermolysis of 12 affording 13, 14, and 2,4,6-tri-t-butylaniline demonstrated oxygen or sulfur migration in the thiosulfinate type compound. Bromine reacted with 1 to give bis(2,4-di-t-butyl-6-methylphenyl)sulfur diimide probably via a thionitroso intermediate. Neither trimethyloxonium tetrafluoroborate nor trimethylsilyl chloride reacted with 1.
Catalytic Hydrolysis of p-Nitrophenyl Esters in the Presence of Representative Ammonium Aggregates. Specific Activation of a Cholesteryl Nucleophile Bound to a Dialkylammonium Bilayer Membrane
Authors: Okahata Yoshio , Ando Reiko , Kunitake Toyoki 
Published: July 2006

Abstract
Catalytic hydrolysis of p-nitrophenyl esters (acetate and nonanoate) by hydroxamate and imidazole nucleophiles was studied at 30 °C in the presence of aqueous aggregates of single-chain (hexadecyl), double-chain (didodecyl and dioctadecyl) and triple-chain (trioctyl) ammonium amphiphiles. These three types of ammonium salts give rise to very different aggregate morphologies. The rate constant of ester cleavage by the nucleophiles was enhanced several hundred folds in the presence of these hydrophobic aggregates. Simple long-chain nucleophiles possessed esterolytic reactivities which reflect the hydrophobic microenvironment of the respective aggregates: single-chain&lt;double-chain&lt;triple-chain. On the other hand, the cholesteryl ester of imidazolecarboxylic acid showed an especially high reactivity when bound to the didodecylammonium bilayer. Cholic acid-derived nucleophiles showed normal reactivity patterns. Apparently, specific binding of the cholesterol derivative to the bilayer is responsible for the unusual catalytic behavior.