No abstract

Phase transfer-catalysed, cobalt carbonyl-catalysed reaction of alkynes with carbon monoxide and methyl iodide affords but-2-enolides ; acylation occurs if dienes instead of alkynes are used as reactants.

Recent advances in ceramics processing indicate that significant materials improvements can be attained by control of dispersion and colloid rheology. New results are presented. where natural and synthetic lipopeptide surfactants were discovered to be excellent dispersants of ceramic powders in toluene. Relatively low concentrations of the lipopeptides promoted rapid dispersion of colloidal II-silicon carbide (SiC) and aluminum nitride (AlN) at slurry concentrations of up to 40 wt% solids. Gravity settling produced up to 5 fold densification improvement over common industrial agents. The new dispersants may find application in a variety of ceramic, pharmaceutical and colloidal processes where superior control of dispersion, slurry rheology and product density are required.

Aren-Diolelin-Ruthenium(0j-Komplexe sind nach der ,,Grignard-Methode" erhalten worden: J . Miiller, C . G . Kreiter, B. Mertschenk, S. Schmitt, Chem. Ber. 108, 273 (1975); zit. Lit. 7: A . Albright, R. Hoffmann, unveroffentlichte Ergebnisse; vgl. auch Chem. Ber. 111, 1578 (1978). Von Eisenkomplexen C6R6FeL2 ( L = C O , PR3 etc.) sind bisher drei bekannt: C6Me6Fe(C0)2 [S. R. Weber, H. H. Brintzinger, J. Organomet.

In Gegenwart des Cobalttetracarbonyl‐Anions erhält man aus Phenylacetylen das Hydroxybutenolid (IV).