Vaucheriaxanthin is 19'-OH and not 19-OH neoxanthin. This structural conclusion was borne out by mass, PMR and infrared (IR) spectra from the free pigment and its derivatives (vaucheriaxanthal, vaucheriaxanthal-diacetate, vaucheriaxanthal-diacetate-mono (trimethylsilyl) -ether, vaucheriaxanthintriacetateand triacetate-monosilanate, vaucheriaxanthin-dimethylether) and by comparison of the charac...

We describe the preparation of [2,4,16,16-2H4]estradiol-17 beta. The method for quantitative determination of subpicomole amounts of estradiol-17 beta (trimethylsilyl ether derivatives) by gas-liquid chromatography-mass spectrometry with multiple ion detector and with [2H4]estradiol-17 beta as the carrier is presented and characterized. Values for serum samples, as measured by radioimmunoassay ...

Study of interaction between catechol and tetraethylene glycol dichloride in the n-butanol media, resulting with benzo-15-crown-5 production. Production of nitroand amino-derivatives of benzo-15-crown-5. Determination of their thermogravimetric characteristics. keywords: benzo-15-crown-5, catechol, tetraethylene glycol dichloride, crown ether, gas liquid chromatography, chromate-mass spectrometry

We report, for the first time, an in situ formation of two-component hydrogels from pyridine derivatives of poly(aryl ether) dendrons and tartaric acid. The two-component system (dendron + acid) undergoes J-type aggregation, leading to fibrillar type self-assembly in THF-water mixture along with blue (470 nm) and green (500 nm) intrinsic emissions.

Two new perylene bisimide (PBI) derivatives possessing crown ether receptors at the 1,7 bay-positions and solubilizing ionic imide substituents were synthesized and their self-assembly properties in the presence of different metal ions were studied, revealing highly selective barium ion templated self-assembly of 15-crown-5 functionalized PBI into H-type dimer aggregates.

The reaction of 3-lithiothiophene with alkyl chloromethyl ether yielded 3-alkoxymethylthiophenes, which were electrochemically polymerized to give conducting polymer films. The conductivity of poly(3-ethoxymethylthiophene) was higher than that of poly(3methoxymethylthiophene), indicated that a longer side chain homologue exceptionally shows higher conductivity. keywords: Electrochemical polymer...

[reaction: see text] Herein we report a new set of silyl ether reagents for determining the enantiomeric purity and absolute stereochemistry of secondary alcohols. These derivatives are easily synthesized, provide straightforward spectroscopic results, and allow for facile recovery of the original chiral alcohol.

Preparation in excellent yields of cyclobutyl benzofuran-2-yl- and naphthofuran- 2-yl-ketones, the corresponding ketoximes and thiosemicarbazones, ether derivatives of the ketoximes and thiazoles derived from the thiosemicarbazones are described. Two of the synthesized compounds have been tested against eight different microorganisms and found to be active against some of the species studied.

3α,5α-Cyclocholestan-6β-yl alkyl and aryl ethers were proved to be efficient cholesteryl donors in the electrochemical synthesis of glycoconjugates. 3α,5α-Cyclocholestan-6β-ol (i-cholesterol) and its tert-butyldimethylsilyl ether can also be used for this purpose. The i-cholesterol derivatives show similar reactivities to those of previously studied 3α,5α-cyclocholestan-6β-thioethers.

[structure: see text] The title compounds were synthesized by applying the 1,3-dipolar cycloaddition reaction of aldehyde-based poly(benzyl ether) dendrimers and sarcosine (N-methylglycine) to [60]fullerene (C(60)). The dendritic building blocks used to functionalize C(60) displayed cubic and hexagonal columnar phases. The fullerene derivatives showed rectangular columnar phases of c2mm symmetry.