Bildung von Estern und Lactonen durch Silberionen-Katalyse

A mild and efficient method for the preparation of esters has been found in the silver ion induced reaction of alcohols with 2-pyridyl esters of thiocarboxylic S-acids. Examples are given to show the utility of this push button activation for the rapid formation of macrocyclic lactones and esters at room temperature under non-basic conditions.     

Umsetzungen von Dialkylaminofluorarsanen mit Halogenwasserstoffen

Reactions of Dialkyl Aminodifluoroarsines with Hydrogen Halides. Diethylaminodifluorarsines react with hydrogen halides and CH₃J under formation of AsF₂X and AsFX_2. Under various conditions rearrangements occur resulting in AsX₃ and AsF_3.     

Umsetzungen von Methylisonitril mit Aluminiumverbindungen

Ohne Zusammenfassung

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Reactions of methylisocyanide with aluminium compounds (Short communication)

     

Herstellung und Umsetzungen von β-Lactamen

The cycloaddition of N-chlorosulfonyl-isocyanate with isoprene, butadiene and a polyolefin as well as the reaction of ketenes with some bis-azomethines were investigated. Suitably substituted bis-azomethines could be separated in the rac. and the meso-form. The reactivity of the azetidinones towards hydrolysis and hydrogenation was tested. Attempts to polymerise 4-vinyl-azetidin-2-one, polyazetidinone and N-substituted bis-azetidinones to give cross-linked poly-β-amides were not successful.     

Umsetzungen von 2,2,3,3-Tetrafluorpropanol mit Metallchloriden

Zusammenfassung TiCl₄, VOCl₃, NbCl₅ und TaCl₅ bilden mit 2,2,3,3-Tetrafluorpropanol Esterchloride, während GeCl₄, SnCl₄ und SbCl₃ unter gleichen Bedingungen nicht reagieren und SbCl₅ eine Koordinationsverbindung bildet.     

Umsetzungen von Dilithio-nitroalkanen und -allylnitroderivaten mit Carbonylverbindungen

Reactions of dilithio-nitroalkanes and dilithio-allynitroalkanes with carbonyl compounds Primary nitro compounds can by acylated via dilithium derivatives 5 with carbonic-acid derivatives to give α-nitro esters 6a – i and with carboxylic-acid esters and anhydrides to give α-nitroketones 6j – q . In the reaction of 1-nitro-1-buten with two mol-equiv. of butyllithium, the dilithium compound 10 is formed by successive Michael-addition and nitronate deprotonation. Dilithium derivatives 5 also react with ketones and benzaldehyde (→ 18a – g ); the nitro aldols 25 and 26 are likewise formed by addition of doubly deprotonated allylic nitro compounds. Some of the products have been further transformed by reduction or by Nef-reactions to the hydrochloride of the α-amino-acid 26 , to 2-amino-alcohols 28a and 28b , to α-hydroxyamino-acid esters 27a – c , to α-hydroxyimino esters 35 and 36 , to α-hydroxyimino ketones 31 and 33 , to the α-diketone 34 , and to the α-keto ester 37 .     

Die Bildung von Ammoniak bei biochemischen Umsetzungen

Ohne Zusammenfassung     

Einige Umsetzungen von 2-Aryl-indandionen-(1,3)

Zusammenfassung Es wird die Synthese des 2-(o-Carboxyphenyl)-indandions-(1,3) (VIIa) und einiger Derivate beschrieben. Das chemische Verhalten dieser Verbindungen, die zum Teil als Zwischenstufen für die Synthese des o-Carboxyphenylnitromethans (Ia) in Frage kommen, wurde studiert. Der Äthylester und der Phenylester von (Ia) wurde dargestellt.     

Umsetzungen von Diacetyl, Hydroxylamin und Metallionen unter Bildung von Chelaten

Ohne Zusammenfassung     

Umsetzungen von Meldrumsäure mit Isocyanaten und Isothiocyanaten

Summary Meldrum's acid (1) reacts with isothiocyanates and LiH as base, yielding after alkylation the ketene-S,N-acetales3,4 and5. Protonation of the lithium-thiolate2 gives the thioamides7 with tautomers8, which can be methylated with diazomethane to9. From1 and7 it is possible to obtain the amides12.2 reacts with -bromo-carboxylic esters and bromo-acetone, yielding thiazolidones15,16 and thiazolines18.

     

Umsetzungen von Tetrafluor-1,2-ethandisulfenyldichlorid mit Ketonen und Olefinen

Reactions of Tetrafluoro-1, 2-ethanedisulfenyldichloride with Ketones and Olefines The reaction of ClSCF₂CF₂SCl 1 with (CH₃)₃C? C(O)CH₃, hexene, diacetyl, cyclobutanone, and H₂C?CHC(O)CH₃ leads to the cyclic and acyclic products 2 – 6 . They are destillable liquids, which have been characterized on the basis of elemental analysis, mass spectra, ¹⁹F-, ¹³C-, and ¹H-n.m.r. spectra. The reaction mechanism will be discussed.