Cyanessigester, Malonester, Methansulfonylessigester werden durch Alkylidenazlactone acyliert. Die Primärprodukte kondensieren leicht zu Alkylidentetramsäuren. Die Acylcyanessigester 2 isomerisieren unter dem Einfluß von Säuren zu Aminopyrrolinonen 3.

Almost the same ligands—completely different metal chelates! Compound 1, R = CO2Me, yields the Mg complex 2 (○ = Mg2+, • = NH 4+) with exohedrally bound ammonium ions by self‐organization; however, 1, R = H, affords the octanuclear Cd complex 3 (○, • = Cd2+). The ammonium ions in 2 can be fully exchanged for primary amines.

For some time we have been working in the field of cage compounds such as [NH,c Fe,Li] (l), originating by the spontaneous self-assembly of preprogrammed bis(bidentate) bridging ligands and suitable metal ions.1'B21 A notable feature of these tetranuclear adamantanoid endoreceptor complexes is their topological equivalence to cryptates (2) .Iz1 [~I We were convinced that the analogy perceived between 1 and 2 is not a special case, but that the use of properly tailored ligands should give access to other metallatopomers. In order to test this hypothesis we treated dialkyl ketipinates 4a,bf5] or tetraketone 4d6' with copper(r1) chloride and aqueous ammonia or potassium hydroxide in methanol, obtaining dark green crystals in each case. The microanalytical data and FAB-MS spectra (FAB = fast atom bombardment) gave initial indications that the products were hexanuclear copper chelate compounds (5) of the general composition [MOH(Cu,L:),].6HOR2, constituting host guest systems topologically equivalent to well-known organocrown ether sandwich complexes 3 [for example, KI(benzo[l5]crown-5),] .I7] In principle, the composition of a coronate is dependent on the cavity diameter of the host. Correspondence between the size of host and guest leads to complexes with 1 : 1 stoichiometry, whereas "oversize" cations result in sandwich complexes with 2: 1 stoichiometry.

Die Titelverbindungen 1 setzen sich mit Natriummethylat unter Substitution zu 5-[(Z)-a-Methoxyalkyliden]-3-pyrrolin-2-onen 2 sowie, unter Ringerweiterung, zu 5-Hydroxy-2-pyridonen 3 um. Das Produktverhaltnis hangt von den Substituenten und der Art des Alkoholats ab. 2b ist ein Naturstoff-Analogon (,,Azafadyenolid"). Reactions of 5-Bromoalkylidene-3-pyrrolin-2-ones, 1The title compounds 1 react with sodium methoxide to give 5-[(Z)-a-methoxyalkylidene]-3-pyrrolin-2-ones 2 by substitution and to yield 5-hydroxy-2-pyridones 3 by ring enlargement. The relative amounts of the products depend on the substituents and the alkoxides used. 2b is an analog of a natural product ("azafadyenolide").Im Zuge unserer Untersuchungen iiber Tetramsauren (Pyrrolidin-2,4-dione) haben wir die Reaktivitat des Halogens in den Benzylidenverbindungen 1 untersucht. Beim Erhitzen von l a mit Natriummethylat auf 150°C erhalt man zwei bromfreie, isomere Substanzen. Hauptprodukt ist das erwartete methoxylierte Pyrrolinon 2 a. Wie bei analogen cyclischen P-Ketoestern ublich 2,3), tritt durch Erhitzen in wasserhaltigem Essigester Verseifung und Decarboxylierung ein; man isoliert die Tetramsaure 2d. Bei der Methylierung von 2a mit Diazomethan erhalt man als einziges Produkt den Methylether 2e. Entsprechend entsteht durch Methylierung von 2d der Ether 2b, der als ha-Analogon des Naturstoffs Fadyenolid4) von Interesse ist.

Dedicated to Professor Dieter Seebach on the occasion of his 65th birthdayThe title compounds were prepared starting from pyrrolinone 4. Nucleophilic-displacement and ringclosure reactions yielded the dithiolopyrrole 5a, which formed salts with electrophiles (7, 8) as well as with bases. The crystal structure of 5a was determined. Oxidation of the dithioles 5a and 6a led to S(2)-oxides (10a, 11a) and the corresponding S(2)-dioxides (10b, 11b) depending on reaction conditions. The thiosulfinate 10a was converted by a ring-opening/ring-closure reaction sequence to the bicyclic sulfinamide 12. The oxidative addition reactions of [Pt(h 2 -C 2 H 4 ) (PPh 3 ) 2 ] (14) with the disulfides 5a and 13 led to the dithiolatoplatinum(II) complexes 15 and 16, respectively. Complex 16 was characterized structurally. The sulfenato-thiolato complex 17 was synthesized via reaction of 14 with the thiosulfinate 10a. The thiosulfonato Pt II complex 18 was prepared by an oxidative insertion of Pt 0 into the CÀS bond of the corresponding thiosulfonate 10b. Furthermore, complex 18 was characterized by single-crystal X-ray-diffraction studies.