bluuebunny/crossref_metadata_2025_split huggingface dataset:
Substituted Bisphenols as Antioxidants for Autoxidation of Tetralin
Authors: Yamada Fukiko , Nishiyama Tomihiro , Yamamoto Masahiro , Tanaka Kazunori 
Published: July 2006

Abstract
The antioxidative activities of nineteen compounds of seven series of alkylidene- and benzylidenebisphenols were evaluated by means of an oxygen-absorption method at 60 °C for tetralin. The electrochemical oxidation potentials determined using linear-sweep voltammetry and the 13C NMR chemical shifts (δ) of these compounds were obtained. These data were associated with the antioxidative activities. In particular, the activities exhibited by the induction period (min) were found to closely correlate with the 13C chemical shifts of the ipso-carbon of the OH substituent (corr. coeff.=0.991). Very good activities have been observed with a series of 2,2′-alkylidene- and benzylidenebis(4,6-dimethylphenol) derivatives.
Extraction Spectrophotometric Determination of Bismuth(III) with Iodide and Amidines
Authors: Ghosh Alpana , Patel Khageshwar Singh , Mishra Rajendra Kumar 
Published: July 2006

Abstract
A new simple and rapid spectrophotometric method for the extraction and determination of bismuth(III) is described. The reaction of N,N′-diphenylbenzamidines and its 10 derivatives (HA) with bismuth(III) in presence of iodide have been investigated photometrically in chloroform. The value of molar absorptivity of the complexes with these compounds lies in the range (0.84–1.35)×104 l mol−1 cm−1. Of these, the most sensitive compound N-(2-methylphenyl)-N′-phenylbenzamidine hydrochloride (MPPBA) was selected for detailed studies. The detection limit of the method is 0.2 μg Bi cm−3. The elements which are commonly associated with the metal e.g. Cu, Ni, Co, Mn, Cr, Zn, Hg, Ti, Zr, Mo, W, V, Al, Sb, etc. do not interfere. The method has been applied for the determination of the metal to soil and ore.
Studies of Collectors. X. Complexing Ability of Amino Hydroxamic Acid Ligands with Dioxouranium(VI) in Aqueous Solution
Authors: Koide Yoshifumi , Uchino Masazumi , Shosenji Hideto , Yamada Kimiho 
Published: July 2006

Abstract
Complexing ability of ligands bearing hydroxyaminocarbonyl group and amino group with UO22+ in an aqueous solution were examined by the potentiometric method using MINIQUAD program. Stability constants of 2-aminoacetohydroxamic acid complex with UO22+ are logβ1=10.45, logβ2=18.95. They are far larger than those of acetohydroxamic acid complexes. The β1 and β2 are almost the same as β1 and β2 of the acetamide oxime (acetoamidoxime) complexes.
The Reaction of N″-Cyanoguanidine with Formaldehyde. IV. The Formation Pathway of 4-Cyanoimino-3-(methoxymethyl)perhydro-1,3,5-oxadiazine
Authors: Shiba Ryuichi , Takahashi Miyuki , Ebisuno Toichi , Takimoto Michiaki 
Published: July 2006

Abstract
An investigation of reactions involving N″-cyanoguanidine (CG) and its methyl derivatives with formaldehyde as well as the consideration of the molecular structures of CG and 4-cyanoimino-3-(methoxymethyl)perhydro-1,3,5-oxadiazine elucidated the formation pathway of the latter compound from CG: CG → N-hydroxymethyl N″-cyanoguanidine → N,N′-bis(hydroxymethyl)-N″-cyanoguanidine → 4-(cyanoimino)perhydro-1,3,5-oxadiazine → 4-cyanoimino-3-(hydroxymethyl)perhydro-1,3,5-oxadiazine → 4-cyanoimino-3-(methoxymethyl)perhydro-1,3,5-oxadiazine.
Oxidation Using Quaternary Ammonium Polyhalides. V. Selective Oxidation of Benzyl Alcohols by the Use of Benzyltrimethylammonium Tribromide
Authors: Okamoto Tsuyoshi , Uesugi Takeshi , Kakinami Takaaki , Utsunomiya Tomohisa , Kajigaeshi Shoji 
Published: July 2006

Abstract
The reaction of several substituted benzyl alcohols with 1 equiv of benzyltrimethylammonium tribromide (BTMA Br3) in carbon tetrachloride under basic or neutral conditions gave the corresponding benzaldehydes, and with 2 equiv of BTMA Br3 in aqueous alkaline solution and subsequent acid hydrolysis gave the corresponding benzoic acids, respectively, in satisfactory yields.
Myeloperoxidase Catalyzed Bromination of Nucleic Acid Bases and Related Compounds
Authors: Itahara Toshio , Ide Naoko 
Published: July 2006

Abstract
Oxidation of cytosine, uracil, adenine, cytidine, and 2′-deoxycytidine by myeloperoxidase in the presence of hydrogen peroxide and potassium bromide in sodium acetate buffer solution at pH 5.0 resulted in bromination of the substrates. A comparison of bromination of 1,3-dimethyluracil catalyzed by peroxidases such as myeloperoxidase, lactoperoxidase, chloroperoxidase, and horseradish peroxidase was also studied.
NMR Determination of Association Constants for Aqueous Calixarene Complexes and Guest Template Effects on the Conformational Freedom
Authors: Shinkai Seiji , Araki Koji , Matsuda Tsutomu , Manabe Osamu 
Published: July 2006

Abstract
The association constants (K) for aqueous complexes with water-soluble p-sulfonatocalix[n]arene (1n: n=4, 6, and 8) were determined by the NMR method. It was found that 14 and 16 form 1 : 1 complexes with guest molecules (trimethylanilinium chloride and 1-adamantyltrimethylammonium chloride), whereas 18 forms 1 : 2 18/guest complexes. The finding supports the view that calixarenes 1n’s are capable of molecular recognition on the basis of the ring size. Examination of the thermodynamic parameters for the association process established that the complexation with 14 is mainly due to the electrostatic force, whereas that with 16 and 18 is mainly due to the hydrophobic force. The coalescence temperatures (Tc’s) for calixarene ring inversion were subject to the template effect by these molecules. The activation parameters for the rate of ring inversion were estimated by a computer-assisted spectrum simulation: it was found that the Tc increase, observed in the presence of these guest molecules acting as templates, is caused by the increase in ΔH\eweq. These findings provide new insights into the association characteristics of water-soluble calixarenes.
Synthesis of 2-Amino-2-deoxy-α-d-altrofuranoside Derivatives from 2,3-O-Isopropylidene-d-glyceraldehyde via Bicyclic β-Lactam Intermediates
Authors: Shiozaki Masao , Ishida Noboru , Sato Sadao 
Published: July 2006

Abstract
A bicyclic β-lactam (4), obtained from 2,3-O-isopropylidene-d-glyceraldehyde in 3 steps, was converted to methyl 2-benzamido-2-deoxy-5,6-O-isopropylidene-3-O-(3-chlorobenzoyl)-α-d-altrofuranoside (24) through an additional 8 steps by utilizing the β-lactam nitrogen via the oxidative decarboxylation of diacyl peroxide (23). Additionally, it was shown that the bicyclic β-lactam intermediate is a suitable precursor for 2-amino-3-(branched-chain)-2-deoxy-d-furanoside derivatives.
The Structure of Rotungenoside, a New Bitter Triterpene Glucoside from Ilex Rotunda
Authors: Nakatani Munehiro , Hatanaka Shuichi , Komura Hajime , Kubota Takashi , Hase Tsunao 
Published: July 2006

Abstract
A new bitter triterpene ester glucoside have been isolated along with known bitter triterpene glucoside peduncloside and some minor triterpenes ulsolic acid, rotundic acid, and rotungenic acid from the unripe fruits of Ilex rotunda. The structure was characterized as β-d-glucopyranosyl 3β,19α,24-trihydroxyurs-12-en-28-oate by spectral data and chemical means.
Novel Structures of 1:1 Complexes of 1,4,7,10,13-Pentaoxa-, 1,13-Dioxa-4,7,10-trithia[13]- and 1,4,7,10,13,16-Hexaoxa[16](1,1′)ruthenocenophanes with HgCl2: Metal–Metal (Ru–Hg) Bond Formation
Authors: Sato Sadao , Sato Masaru , Akabori Sadatoshi 
Published: July 2006

Abstract
The structures of 1:1 complexes (3b, 4b, and 5b) of 1.4,7,10,13-pentaoxa-, 1,13-dioxa-4,7,10-trithia[13]- and 1,4,7,10,13,16-hexaoxa[16](1,1′)ruthenocenophanes (3a, 4a, and 5a) with HgCl2, and 3a have been determined by the single-crystal X-ray diffraction method. The complexing forms of the three complexes are quite similar to each other. Crystal data: 3b, triclinic, space group P\bar1, a=12.043(3), b=10.759(2), c=8.529(2) Å, α=98.76(2), β=101.22(2), γ=77.03(2)°, U=1049.5 Å3, Z=2, Dc=2.19 g cm−3, μ(Mo Kα)=84 cm−1. 4b, triclinic, space group P\bar1 a=17.100(3), b=8.986(1), c=8.618(2) Å, α=105.17(1), β=62.24(1), γ=100.54(1)°, U=1128.1 Å3, Z=2, Dc=2.18 g cm−3, μ(Mo Kα)=81 cm−1. 5b, monoclinic, a space group P21⁄a, a=26.881(7), b=10.344(3), c=8.414(2), β=96.97(2)°, U=2322.2 Å3, Z=4, Dc=2.11 g cm−3, μ(Mo Kα)=76 cm−1. 3a, triclinic, space group P\bar1, a=11.107(1), b=8.816(1), c=9.788(1) Å, α=70.48(1), β=99.76(1), γ=101.31(1)°, U=877.6(2) Å3, Z=2, Dc=1.59 g cm−3, μ(Mo Kα)=9 cm−1. Only the Ru atom of the ruthenocene nucleus of these complexes was coordinated to HgCl2 with a slightly distorted trigonal-planar configuration. The distances between the Ru and the Hg atoms are 2.683(3), 2.704(1), and 2.696(2) Å, respectively.
The Removal of Nitrogen Monoxide by the Dry Iron(II) Complex Immobilized on Chelate Resin. The Preparation and Characterization of the Complex
Authors: Toshima Naoki , Asanuma Hiroyuki , Hirai Hidefumi 
Published: July 2006

Abstract
A new dry-type adsorbent for nitrogen monoxide was successfully prepared from an iron(II) salt and a chelate resin containing iminodiacetic acid moieties. The capability of adsorbing nitrogen monoxide depended greatly on the method of preparation. The very active adsorbent was prepared by mixing 31.4 mmol of iron(II) sulfate and a commercial chelate resin containing 21.0 mmol of iminodiacetic acid moieties; the mixture was dried after the solid parts had been washed with methanol. The resulting solid adsorbent could adsorb more than 99% of the nitrogen monoxide from 6 dm3 of nitrogen gas containing 1000 ppm of nitrogen monoxide within 25 min. This high capability for adsorbing nitrogen monoxide was derived from the increase in the surface area (43.1 m2 g−1) of the resin-immobilized iron(II) complex upon washing with methanol. The mechanism for the increase in the surface area is also discussed.
Unusually High Oxidation Half-Wave Potentials of Di- and Trichalcogena[3]ferrocenophanes. The Effect of Chalcogen Atoms in the Bridge
Authors: Ushijima Hirobumi , Akiyama Takeo , Kajitani Masatsugu , Shimizu Kunio , Aoyama Masahide , Masuda Shigeru , Harada Yoshiya , Sugimori Akira 
Published: July 2006

Abstract
1,2,3-Trithia[3]ferrocenophane (1a) and related compounds show a well-defined reversible one-electron oxidation wave (Fe(III)/Fe(II)) in cyclic voltammetry. The [3]ferrocenophanes with S and/or Se atoms in the bridge show unusually high oxidation half-wave potentials which have not been observed either in [3]ferrocenophane or in 1,1′-bis(methylchalcogeno)ferrocenes. The effect of chalcogen atoms at the 1,3-positions in the bridge on the positive shift of half-wave potentials is larger than that at the 2-position. Two kinds of electron-attracting effects of chalcogen atoms at the 1,3-positions in the bridge are proposed: an inductive electron-attracting effect (“through-bond” effect) and the interaction between the d-orbitals of Fe and chalcogen (“through-space” interaction). The role of the sulfur atom at the 2-position in the bridge is to stabilize the electron attracted by the sulfur atoms at the 1,3-positions by conjugation of three sulfur atoms.
Thermal Behavior and Characterization of Some 2-Oxazolidinone Derivatives
Authors: Shimasaki Choichiro , Hayase Shuichi , Murai Atsuko , Takai Junko , Tsukurimichi Eiichi , Yoshimura Toshiaki 
Published: July 2006

Abstract
Four kinds of 2-oxazolidinone derivatives, (1) [5-phenoxymethyl-3-phenylcarbamoyl-2-oxazolidinone (1a), 2,4-bis(2-oxo-3-oxazolidin-3-ylcarbonylamino)toluene (1b), N,N′-bis(2-oxo-3-oxazolidin-3-ylcarbonyl)-1,6-hexanediamine (1c), and 1,4-bis(3-phenylcarbamoyl-2-oxo-5-oxazolidin-5-ylmethoxy)benzene (1d)], were prepared with the addition of 2-oxazolidinone, 5-phenoxymethyl-2-oxazolidinone (2), and 1,4-bis(2-oxo-5-oxazolidin-5-ylmethoxy)benzene (3) to mono- or diisocyanates by using N,N-dimethylformamide or benzene as solvents and 1,4-diazabicyclo[2.2.2]octane as a catalyst. Compound 1 was found to be thermally stable by thermal analysis. DSC curves of these compounds revealed an endothermic peak due to melting, except for 1d which was obtained from 3. The main fragmentation mechanism by electron impact for 1 was found to consist of two processes: simple cleavage and a rearrangement reaction. Further, each process was followed by cleavage modes. The proportion of fragment ions containing the benzene ring in the main fragmentation was greater than 80%. From the DTA-TG/DTG curves, the difference between EI-cleavage and thermal decomposition for 1a was elucidated.
End Groups of Poly(methyl methacrylate) as a Function of Molecular Weight Determined by Pyrolysis-Gas Chromatography
Authors: Ohtani Hajime , Tanaka Minoru , Tsuge Shin 
Published: July 2006

Abstract
End groups of poly(methyl methacrylate) (PMMA) radically polymerized with benzoyl peroxide (initiator) in toluene solution were investigated by pyrolysis gas chromatography as a function of molecular weight. The number-average molecular weights (\barMn) of fractionated PMMA samples were estimated from the relative peak intensities of characteristic pyrolysis products and were compared with those determined by size exclusion chromatography. The observed result suggested that the chain transfer reactions to the monomer might yield relatively smaller PMMA molecules. Furthermore, the relative peak intensities among aromatic products which reflect three kinds of aromatic chain ends were correlated to the (\barMn) of the fractionated PMMAs. The result suggested that the chain transfer reaction to the solvent also tended to yield relatively smaller PMMA molecules whereas the polymerization initiated by the phenyl radical from the initiator yielded relatively larger PMMA molecules under given polymerization conditions.
35C1 NQR of 1:2 Complexes of SnCl4 with Several Nitriles
Authors: Mishima Mitsuo , Okuda Tsutomu 
Published: July 2006

Abstract
35C NQR spectra have been obtained for the complexes of SnCl4·2RCN (R=CH3, CD3, t-C4H9, or C6H5). The NQR spectra reveal the existence of three crystal modifications in SnCl4·2CH3CN, a stable phase (Form-1) and two metastable ones (Form-2 and Form-3). Form-3 was obtained as a mixture with Form-2. These modifications are suggested to be cis isomers. The complex, SnCl4·2C6H5CN, has likewise yielded three modifications, and the evidence for cis–trans isomerization in this complex has been found from NQR spectra. A Zeeman analysis on single crystals reveals that SnCl4·2t-C4H9CN has a cis form and that its molecular geometry is similar to Form-1 of SnCl4·2CH3CN. In these complexes, the equatorial Cl atoms yield asymmetry parameters of 0.05 to 0.08 and the axial ones negligibly small values. The temperature dependence plot for the NQR frequencies in SnCl4·2CH3CN yields unusual curves. This is attributed to some interaction between the Cl atom and the methyl groups.
NAD(P)+–NAD(P)H Models. 71. A Convenient Route to the Synthesis of Juvabione
Authors: Fujii Masayuki , Aida Tetsuo , Yoshihara Masakuni , Ohno Atsuyoshi 
Published: July 2006

Abstract
Synthesis of juvabione in short steps in a high overall yield has been achieved via the chemoselective reduction with Hantzsch ester (HEH) in the presence of silica gel as a key step.
Convenient and Efficient Tosylation of Oligoethylene Glycols and the Related Alcohols in Tetrahydrofuran–Water in the Presence of Sodium Hydroxide
Authors: Ouchi Mikio , Inoue Yoshihisa , Liu Yu , Nagamune Satoshi , Nakamura Satoko , Wada Kazuhito , Hakushi Tadao 
Published: July 2006

Abstract
Oligoethylene glycols and some related alcohols were efficiently tosylated with p-toluenesulfonyl chloride in a tetrahydrofuran–water (1:1) mixture in the presence of excess sodium hydroxide. This method is advantageous over the conventional tosylation in pyridine both regarding the work-up procedure, the yield, and the purity of the product, and may be potentially useful for the tosylation of certain acid-labile alcohols.
A New Synthesis of β-Keto Sulfoxides from Chloromethyl Aryl Sulfoxide and Aldehydes
Authors: Satoh Tsuyoshi , Fujii Takako , Yamakawa Koji 
Published: July 2006

Abstract
Addition of the carbanion of chloromethyl aryl sulfoxide to aldehyde gave the adduct, which was treated with three-equivalents of lithium diisopropylamide (LDA) to afford β-keto sulfoxide in high overall yield.
Thermally Irreversible Photochromic Systems. Reversible Photocyclization of 1,2-Bis(benzo[b]thiophen-3-yl)ethene Derivatives
Authors: Uchida Kingo , Nakayama Yasuhide , Irie Masahiro 
Published: July 2006

Abstract
1,2-Bis(benzo[b]thiophen-3-yl)ethene derivatives, which possess thermally irreversible and fatigue resistant photochromic properties, were synthesized, cis-1,2-Dicyano-1,2-bis(2-methylbenzo[b]thiophen-3-yl)ethene 1a and 2,3-bis(2-methylbenzo[b]thiophen-3-yl)maleic anhydride 2a underwent reversible photocyclization to produce red-colored closed-ring forms with λmax at 507 nm and 544 nm, respectively. The closed-ring forms were stable for more than 3 weeks at 80 °C. The coloration/decoloration (ring closure/opening)cycles were able to be repeated more than 104 times with keeping the adequate photochromic performance.
Kinetics of the Ligand Substitution Reactions of a Labilized Ruthenium(III) Complex, [Ru{N′-(2-hydroxyethyl)ethylenediamine-N,N,N′-triacetate}(H2O)]
Authors: Ogino Hiroshi , Katsuyama Tetsuo , Ito Setsuo 
Published: July 2006

Abstract
The kinetics of the substitution reactions of [N′-(2-hydroxyethyl)ethylenediamine-N,N,N′-triacetato]-aquaruthenium(III), [Ru(hedtra)(H2O)], with X (Br−, CH3CN, SCN−, and pyridine) to give [RuX(hedtra)] were carried out at 25 °C and I=0.5 mol dm−3. The substitution reactions were found to be unusually rapid. The rate constants of the forward reaction (kf) and of the backward reaction (kb) were kf=0.13±0.01 mol−1 dm3 s−1 and kb=(1.9±0.2)×10−2 s−1 for the reaction with Br−, kf=0.48±0.02 mol−1 dm3 s−1 and kb=(3.0±0.2)×10−2 s−1 for the reaction with CH3CN, and kf=7.5±0.2 mol−1 dm3 s−1 and kb=(1.3±0.8)×10−2 s−1 for the reaction with SCN−, respectively. The kinetics of the reaction of [Ru(hedtra)(H2O)] with py was studied as a function of pH. The observed rate constants of the reaction were separated into two rate constants; the rate constant of the forward reaction of [Ru(hedtra)(H2O)] with py (18±2 mol−1 dm3 s−1) and that of [Ru(OH)(hedtra)]− with py (3.0±1.0 mol−1 dm3 s−1). The mechanisms of the reactions are discussed.
Synthesis and Ion Exchange Properties of Sodium Stannosilicate: A Silver Selective Inorganic Ion Exchanger
Authors: Rawat Jagdish Prasad , Ansari Abdul Aziz 
Published: July 2006

Abstract
An inorganic ion exchanger sodium stannosilicate has been synthesized. Its composition, chemical and thermal stabilities and ion exchange properties have been studied. This material is obtained as hard granules and is very stable at high temperatures. Its ion exchange capacity for Ag+ is 2.25 mequiv g−1. The material shows high selectivity towards Ag+ which has been separated quantitatively from Pb2+, Hg2+, and Cu2+. Recovery of Ag+ from dilute solutions has also been studied.
Normal Vibrations of 4-Methyl- and 4-Methyl-d3-pyridines
Authors: Yoshikai Kazumasa , Hieida Toshikazu , Nibu Yoshinori , Shimada Hiroko , Shimada Ryoichi 
Published: July 2006

Abstract
Assignment of the normal vibrations of 4-methylpyridine was made through the vibrational analyses of the Raman and infrared spectra and also through the normal coordinate calculation. The assignment was confirmed by the study made on 4-methyl-d3-pyridine.
Trimethylsilyl Derivatives of Alkyltrimethylammonium–Kanemite Complexes and Their Conversion to Microporous SiO2 Materials
Authors: Yanagisawa Tsuneo , Shimizu Toshio , Kuroda Kazuyuki , Kato Chuzo 
Published: July 2006

Abstract
Alkyltrimethylammonium–kanemite complexes, having three dimensional SiO2 networks, were allowed to react with a trimethylsilylating reagent to form the trimethylsilylated derivatives. The three dimensional SiO2 networks were retained after trimethylsilylation. The calcined products obtained from the trimethylsilylated products had about 840–880 m2 g−1 in specific surface areas and micro pores with 22–33 Å in average pore diameter. These values were slightly smaller than those of the calcined products obtained from alkyltrimethylammonium–kanemite complexes, which indicated the effect of the trimethylsilyl groups.
Hydrothermal Synthesis of Calcium Silicate of ZSM-5 Structure in Alkali-Metal-Cation-Free Conditions
Authors: Okabe Kiyomi , Matsuzaki Kenji , Hagiwara Hiroyuki 
Published: July 2006

Abstract
Crystalline calcium silicate of ZSM-5 structure was hydrothermally synthesized by using an excessive amount of tetrapropylammonium bromide (TPABr) as an organic base and without using any alkali metal ions in the low pH range. The acidity caused by Ca was verified by IR, NH3-TPD, and methanol conversion.
The Migration of Barium into Zeolite Channels from the Outer Surfaces of Zeolite Crystals
Authors: Sano Tsuneji , Okado Hideo , Shoji Hiroshi , Ikai Shigeru , Takaya Haruo 
Published: July 2006

Abstract
For the ZSM-5 zeolite mechanically mixed with barium carbonate, the migration of barium into the zeolite channels from the outer surfaces of zeolite crystals occurs at 600 °C in both the absence of and the presence of steam, resulting in a modification of the strong acid sites.
Resonance Raman Active Vibrations of Blue Copper Proteins. Normal Coordinate Analysis on 169-Atom Model
Authors: Urushiyama Akio , Tobari Jiro 
Published: July 2006

Abstract
Normal coordinate analyses were performed for three crystallographically defined blue copper proteins: Alcaligenes denitrificans azurin, Pseudomonas aeruginosa azurin, and poplar leaf plastocyanin. A maximum of 485 internal coordinates were specified from a model constructed by the analyzed coordinates of the 169 atoms around the type-1 blue copper site. Mass-group approximation was employed for CH, CH2, CH3, NH, and NH2 groups throughout. With the use of reasonable force constant values, the standard GF calculation method always gives rise to extensive couplings of Cu–S(cysteine) stretching coordinate to the bending coordinates widely distributed in the molecule. Several normal vibrational modes having appreciable PED values of the Cu–S(cysteine) stretching coordinate are correlated with the characteristic RR lines of the blue copper proteins in the 370–450 cm−1 region. Our data indicate that the protein-sensitive variation of the RR pattern might be ascribed to a difference in the peptide structure around the blue copper site, rather than to the structure of the Cu coordination sphere, itself.
Lewis Acid Catalyzed Reaction of o-[1-(Alkylthio)alkyl]phenols: The Generation and Reaction of o-Quinonemethides and Applications to Cannabinoid Synthesis
Authors: Inoue Tsutomu , Inoue Seiichi , Sato Kikumasa 
Published: July 2006

Abstract
o-Quinonemethides were prepared by treating o-[1-(alkylthio)alkyl]phenols with a Lewis acid. The Diels–Alder reaction of the resulting o-quinonemethides was also catalyzed by the Lewis acid. Hexahydrocanna-binol was synthesized according to this method.
Synthesis and Radical Induced Ring Opening Reaction of 1-Trialkylsilyl-2-vinylcyclopropanes
Authors: Miura Katsukiyo , Oshima Koichiro , Utimoto Kiitiro 
Published: July 2006

Abstract
A variety of trialkylsilylvinylcyclopropanes were prepared by two different routes: (a) Cyclopropanation of 1-alkenylsilanes and (b) the reactions of 1-bromocyclopropyllithium with trimethylsilyl chloride. Radical induced ring opening reaction of these cyclopropanes were examined. 1-Dimethylphenylsilyl-2-vinylcyclopropane or 3-methyl-1-trialkylsilyl-2-vinylcyclopropane provided the corresponding homoallylic silane exclusively upon treatment with PhSH, Ph3SnH, n-Bu3SnH, or n-C6F13I. On the other hand, 2-phenyl-1-trimethylsilyl-3-vinylcyclopropane or 2-acetyl-1-trimethylsilyl-3-vinylcyclopropane gave allylic silane selectively.