Poly(vinylidene fluoride)-γFe2O3 magnetic composites

Magnetic metal-polymer composites have been prepared by thermolysis of a metal carbonyl Fe(CO₅) in poly(vinylidene fluoride). These composites comprise ca. 100-Å-diam iron-oxide, γFe₂O₃, ferrimagnetic particles dispersed in the polymeric matrix. Small-angle x-ray studies show that these particles have a radius of gyration in the range 63–315 Å. The composites were prepared with up to ca. 20 wt % iron and were crosslinked, as evidenced by insolubility. Electron diffraction indicating the formation of some FeF₂ suggests metal-fluorine interaction during formation of the composite.     

A Stereospecific Synthesis of (E,Z)-α, β-γ, δ-Diunsaturated Aldehydes,Ketones, and Esters Using the Benary Reaction

The reaction between (Z)-1-alkenyllithium and (E)-β-(N, N-dialkylamino)-α, β-alkenals, (E)-β-(N, N-dialkylamino)-α, β-alkenones or (E)-β-(N, N-dialkylamino)-α, β-alkenoic esters yields mainly (E, Z)-α, β-γ, δ-diunsaturated aldehydes, ketones, or esters and is therefore highly stereospecific.     

Synthesis of 2-hydroxy-6-{[(16R)-β-δ-mannopyransyloxy]heptadecyl}benzoic acid, a fungal metabolite with GABAA ion channel receptor inhibiting properties

An expeditious total synthesis of the physiologically active fungal metabolite 1 is described. The stereoselective formation of its β-δ-mannopyranosidic linkage is achieved in two steps upon reaction of the hexopyranos-2-ulosyl bromide 15 with the glycosyl acceptor 13, followed by reduction of the resulting β-δ-glycos-2-uloside 16. Alcohol 13 was efficiently prepared via a Suzuki reaction of the aryltriflate 11 with the 9-alkyl-9-BBN derivative 10.     

Citrus-Carotinoide. 2. Mitteilung. Synthese von (3R)-β-Citraurin, (3R)-β-Citraurol und (3R)-β-Citraurinin; Aufklärung der Konfiguration von Citrus-Carotinoiden

Citrus-Carotenoids. Synthesis of (3R)-β-Citraurin, (3R)-β-Citraurol and (3R)-β-Citraurinene; Determination of the Configuration of Citrus-Carotenoids (3R)-β-Citraurin, (3R)-β-citraurol and (3R)-β-citraurinene were prepared starting from (3R)-3-acetoxy-β-ionone. Comparison of the chiroptical data of β-citraurin from orange peels with those of the synthetic compound confirmed the 3R-configuration of the natural pigment.