Conjugate additions of the crown-potassium enolate complexes

Achiral and chiral crowns complexed with potassium bases catalyze the Michael additions of enolates to cycloalkenones.     

Network structure consisting of chain-like arrays of gold nanoparticles and silica layer prepared using a nonionic reverse-micelle template

A nonionic reverse-micelle based approach is described for fabrication of a network structure consisting of chain-like arrays of gold nanoparticles, followed by coating process with a uniform silica layer using a sol-gel method. The hexadecyl-poly (ethylene oxide-15) ether (designated C₁₆E₁₅) is used as a template for this study. The effects of a water-to-surfactant molar ratio (w) as well as the concentration of tetraethyl orthosilicate ([TEOS]_oil) are investigated on the resulting organized structures.     

Synthesis of crystalline yttrium oxycarbonate in a single phase

Crystalline yttrium oxycarbonate, Y₂O₂CO₃, was synthesized by our original flux method using the 0.476Li₂CO₃-0.270Na₂CO₃-0.254K₂CO₃ eutectic mixture at 450 °C. The oxycarbonate was characterized by X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), and Fourier-transfer infrared spectroscopy (FT-IR). The Y₂O₂CO₃ prepared by the flux method was a crystalline single phase of hexagonal rare earth oxycarbonate (type-II). This is the first report on the single-phase synthesis of crystalline hexagonal type-II Y₂O₂CO₃.     

Preparation of 4-hydroxy-2-alkenenitriles from phrnylsulfinylacetonitrile with keetones or aldehydes,and its synthetic application to substituted furans

The reaction of phenylsulfinylacetonitrile 1 with ketones or aldehydes gave 4-hydroxy-2-alkenenitriles which were converted to 2- and/or 3-substituted furans by the treatment with diisobutylaluminumhydride(DIBAL) followed by acid hydrolysis.     

Intramolecular Aryl Migration from Tin to Carbon via a Radical Atom-Transfer Process

Triethylborane-induced intramolecular 1,4-aryl migration from tin to a carbon-centered radical is described. Treatment of 3-iodoalkyldimethylphenylstannanes with Et(3)B in benzene at reflux followed by an addition of MeMgI provides 3-phenylalkyltrimethylstannanes in good yield via a radical atom-transfer process.     

Enantioselective tandem O-nitroso Aldol/Michael reaction

This communication presents studies that illustrated nitroso Diels-Alder adduct has been obtained in uniformly high enantioselectivity via a tandem nitroso aldol/Michael reaction using an amine catalyst. The regiochemical outcome of this construction is documented to be the opposite to that of the normal nitroso aldol reaction, which has been determined by X-ray analysis. The reaction of the enone with silver-BINAP catalyst has also been investigated in conjunction with the control of regiochemistry in a stepwise process.     

Isolation of peridinin-related norcarotenoids with cell growth-inhibitory activity from the cultured dinoflagellate of Symbiodinium sp., a symbiont of the Okinawan soft coral Clavularia viridis,and analysis of fatty acids of the dinoflagellate

Two norcarotenoids, 1 and 2, related to peridinin (3) were isolated from the cultured dinoflagellate of the genus Symbiodinium, a symbiont of the Okinawan soft coral Clavularia viridis, which contains in abundance antitumor marine prostanoids such as clavulones. The structures of 1 and 2 were elucidated on the basis of spectroscopic analysis. These compounds showed significant growth-inhibitory activity in vitro toward cancer cells. Analysis of fatty acids of the dinoflagellate was also carried out, suggesting that the marine prostanoids are produced by the host soft coral itself.     

Sterilization of Bacillus spores by converted X rays

Relative sensitivities of endospores of Bacillus pumilus E601, B. subtilis IAM1069, B. megaterium S31 and B. brevis S5 to gamma rays, converted X rays (bremsstrahlung) and electron beams were examined in order to estimate the conditions in which converted X rays kill Bacillus spores. The radiation sensitivities to gamma rays and electron beams of each strain dried on glass fiber filter without additives were found to be almost equivalent, and D values were obtained as follows: 1.5–1.6 kGy for B. pumilus, 1.4–1.5 kGy for B. subtilis, 1.9–2.0 kGy for B. megaterium and 1.6–2.0 kGy for B. brevis. The radiation sensitivities of endospores of each strain to electron beams were slightly lower than those to gamma rays in the dry condition with additives of 2% peptone + 1 % glycerin on glass fiber filters. The increase of radiation resistance in the presence of additives was also observed with X rays, and it was on an intermediate level between those with gamma rays and electron beams. In the dry condition using cellulose filter paper, only the radiation resistances of B. megaterium and B. brevis in the presence of additives B. megaterium and B. brevis in the presence of additives were increased.