Zur Synthese von 3-Desoxy-aldulosonsäuren

The condensation of 2.4-ethylidene-erythrose with the sodium salt of diethyl-phosphono-piperidino-ethylacetate yields an enamino-lacton V which is converted under mild conditions into an α-keto ester, 2-oxo-3-desoxy-gluconic acid, and its quinoxaline derivative.     

Eine neue Synthese von DL-Armentomycin und verwandten 2-Amino-4-polyhalobuttersäuren

A New Synthesis of DL -Armentomycin and Related 2-Amino-4-polyhalobutyric Acids An efficient method for the synthesis of 2-amino-4-halobutyric acids 2 starting from the corresponding ethyl 2,4-polyhalobutyrates 1 is presented (s. Scheme 1). The method is illustrated by a high yield synthesis of the known antibiotic DL -armentomycin (= 2-amino-4,4-dichlorobutyric acid; 2a ).     

Synthese der enantiomeren 2-Pyrrolidinessigsäuren

Synthesis of the enantiomeric 2-pyrrolidineacetic acids. Starting from the enantiomeric Z-prolines ( 1 ) the title compounds 9 were prepared in optically pure form by using the Arndt-Eistert process. It could be shown by chemical correlation that the stereochemical determining step of the reaction sequence, the Wolff rearrangement of the N-acylated diazomethyl ketones 5 , proceeds with strict retention of configuration. Some known chiroptical methods for determination of absolute configuration were applied to the target compounds.     

Synthese von in 2- bzw. 3-Stellung substituierten Alkandiphosphonsäuren

Synthesis of 2- or 3-substituted Alkanediphosphonic Acids Syntheses of substances of the general formula RCX(PO₃H₂)₂ X = OH, H, Cl, NH₂ have been known for a long time. The preparative possibilities for the synthesis of alkanediphosphonic acids containing an amino group or a chlorine atom in the 2- or 3-position were limited, only 2 substances from this class of compounds being known. Further examples of this class of substances have been synthesized.     

Eine neue Synthese von 1,2,3-Triphenylbenzol

Ohne Zusammenfassung