VERFAHREN ZUR HERSTELLUNG VIERGLIEDRIGER CYCLISCHER KETONE

A process for the preparation of a cyclobutanone of the formula in which R1 to R6 each independently is a hydrogen, halogen, cyano, alkoxy, alkoxycarbonyl, carboxamido, dialkylphosphono, alkyl, cycloalkyl, aryl, aralkyl or alkenyl radical, or two of them together with the carbon atom to which each is linked form a ring, comprising reacting an N,N-disubstituted carboxylic acid amide of the formula in which R7 and R8 each independently is an alkyl, cycloalkyl, alkenyl, aryl or aralkyl radical or together form a ring, with an inorganic acid halide, and then reacting the product with a tertiary amine, an olefin of the formula and a Lewis acid, and subsequently hydrolyzing the mass. Preferably isobutyric acid dimethylamide is employed as the carboxylic acid amide, phosgene is employed as the inorganic acid halide, triethylamine is employed as the tertiary amine and zinc chloride or titanium tetrachloride is employed as the Lewis acid. The products are known intermediates for insecticides.