Prostaglandin H2 (PGFL) has been prepared by chemical synthesis from PGF;,,. The synthesis proceeds from the intermediate 9/3,1 l/3-dibromo-9,l 1-dideoxyprostaglandin F2iv to the endoperoxide PGFL in 17-24% yield upon reaction of the dibromide with silver trifluoroacetate and hydrogen peroxide in diethyl ether. Synthetic PGFL was purified by high-pressure liquid chromatography and was characterized by comparison with a biological sample and by conversion to PGF2" methyl ester, PGE2, and PGFL methyl ester under appropriate reaction conditions. Synthetic PGFL aggregates human platelet rich plasma that has been preincubated with indomethacin.

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Direct proof of intermolecular compositional inhomogeneity of a metallocene polyethylene copolymer has been obtained using a cross-fractionation (CF) technique. The ethylenell-hexene copolymer sample was synthesized using a Zr-based homogeneous metallocene catalyst. A solvent gradient fractionation (SGF) applied to the whole polymer material has produced nearly monodispersed molecular weight distribution fractions. The component molecules of a representative SGF fraction are then further sorted out, using a temperature gradient fractionation technique, according to their short-chain branching (SCB) differences. Molecular characterization of the resulting C F fractions reveals the presence of significant intermolecular SCB content differences among the components of the sample material.

Aus der Vorstufe (I) kann nach einem verbesserten Verfahren mit Silbertrifluoracetat und Wasserstoffperoxid der Prostaglandin‐Hzmethylester (II) hergestellt werden.

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