Hellmuth Reinshagen

Synthese der 5-Arylpyrromethene

The syntheses of some 5-arylpyrromethenes are described, and their biological activities related to that of metacycloprodigiosin.

Synthese des 12-(3-Methoxy-5-phenyl)-2-pyrrolylmethylen-2H-[9](2,4)-pyrrolophans Ansamycine, 4. Mitt.: Chemie der Metacycloprodigiosine

The introduction of an acetoxy group into the pyrrol nucleus with lead tetraacetate is described and therewith involved mechanistic aspects are discussed. According to this method we obtained the aldehyde13 required for the synthesis of 3-methoxypyrromethene16.

Ansamycine, 5. Mitt., Chemie der Metacycloprodigiosine

In order to obtain a better partition of a prodigiosin derivative in biological media, two hydroxy groups were introduced into theansa-part of the molecule. The synthesis of the title compound is described in detail.

Synthesen an Ansabrücken von (2,5)-Pyridinophanen I

Abstract(2,5)-Pyridinophanes were chosen as model compounds for synthetic manipulations at the end of ansabridges. Some selective transformations of the carbonyl function in [11] (2,5)-Pyridinophan-11-on (1) are reported. Lactams (“Ansanicotinamide”), lactones, tetrazoles and other derivatives were obtained in good yield.

Ansamycine, 1. Mitt.: Chemie der Metacycloprodigiosine, Synthese des [9](2,4)Pyrrolophans

Some syntheses of [9](2,4)pyrrolophane are described.

Chemie der Metacycloprodigiosine

Alkylation of 3-hydroxypyrromethenes and 3-hydroxypyrrole derivatives with trialkyloxoniumtetrafluoborate afforded 3-alkoxy-derivatives whereas other methods of alkylation (dimethyl sulfate, methyl fluorosulfonate, diazomethane) led only to N-methylated compounds. The structure assignments were based on chemical and spectroscopic data.

Synthesen an Ansabrücken von (2,5)-Pyridinophanen II

Studies were made on synthetic transformations of the ansabridge in (2,5)-pyridinophanes. Functionalisation in position 1 is achieved by treatment of (2,5)-Pyridinophane-N-Oxide with acetic anhydride. It is shown that both ends of the bridge·can be manipulated selectively and independently. As was shown by NMR-spectroscopy, the internal rotation of the pyridin nucleus depends on the ring size and the substitution.