Ein einfacher Zugang zu 3-Amino-nocardicinsäure. Modifikationen von Antibiotika. 17. Mitteilung [1]

A Simple Route to 3-Amino-nocardicinic Acid Starting from nocardicin A ( 1 ), a novel and efficient procedure for the preparation of 3-amino-nocardicinic acid ( 4 ) and its protected derivatives 6 and 8–11 is described.     

Neue β-Lactam-Antibiotika. Zur Funktionalisierung von 3-Hydroxy-3-cephem-4-carbonsäureestern durch die Wittig-Reaktion. Modifikationen von Antibiotika. 16. Mitteilung [1]

New β-lactam antibiotics. Functionalisation of 3-hydroxy-3-cephem-4-carboxylic esters through the Wittig reaction The 3-hydroxy-ceph-3-em-esters 1a, b reacted smoothly with stabilized phosphor-ylids to give a series of derivatives which were converted into the microbiologically active acids 14a, c, 15c and 20 by known procedures. The synthesis of the amides 23, 24, 26 and of the ester 28 from the 3-carboxymethyl-derivative 19 is also reported.     

Neue β-Lactam-Antibiotika. Über Derivate der 3-Hydroxy-7-amino-ceph-3-em-4-carbonsäure. Modifikationen von Antibiotika, 10. Mitteilung [1]

3-Hydroxy-ceph-3-em-esters 5 a – c , versatile intermediates for the preparation of new β-lactam antibiotics, were obtained by ozonolysis of the corresponding 3-methylidene-esters 3 a – c . Reduction and elimination gave the 3-unsubstituted ester 13 ; derivatives 16 a – c and 20 – 22 resulted from O-alkylation. The 3-methoxy-esters 16 a – c were converted into the corresponding acids 23 a – d . Several other transformations of the β-ketoester system are described.     

Die Umwandlung von Dextrin in Traubenzucker

Ohne Zusammenfassung     

Die Synthese von 4-Alkylchinuclidinen. Chinuclidinreihe, 11. Mitteilung

The syntheses of 4-methyl-, 4-ethyl-, 4-isopropyl-and 4-t-butylquinuclidine are described. The key step in the synthesis of 4-t-butylquinuclidine involves a modified Koch-Haaf reaction leading from a δ-amino-tert. alcohol to an ester of the homologous acid.     

Neue β-Lactam-Antibiotika. Über die Darstellung und Decarbonylierung von 3-Formylcephem-Verbindungen. Modifikationen von Antibiotica, 12. Mitteilung [1]

Benzhydrylic esters of 3-unsubstituted cephem-4-carboxylic acids of types 9 and 10 (Scheme 2) are prepared by decarbonylation of esters of 3-formylcephem compounds of type 2 with tris-triphenylphosphine-rhodium chloride. The preparation of the starting materials 2 and 5 , as well as of the nucleus 13 is described.     

Die Struktur der Drevogenine. 3. Mitteilung Struktur von Drevogenin A,B und D. Glykoside und Aglykone, 279. Mitteilung

The treatment of drevogenin P with isovaleryl chloride in pyridine gave an amorphous 3,12-di-O-isovaleryl-drevogenin P ( 4 ), which, on energetic acetylation, was converted into 3-O-isovaleryl-drevogenin A ( 5 ). This could be isolated in crystalline form and was converted through mild alkaline hydrolysis into drevogenin A. Hence drevogenin A could be classified as 11-O-acetyl-12-O-isovaleryl-drevogenin P. Indirectly, the structure of drevogenin B could be deduced to be most probably that of 11α-mono-O-acetyl-drevogenin P. Some details of the earlier given structures [1] are corrected here. Drevogenin D has an 11α-hydroxyl group.     

Die Glykoside Vincetoxicum hirundinaria MEDIKUS. 3. Mitteilung: Struktur von Hirundigenin und Anhydrohirundigenin. Glykoside und Aglykone, 318. Mitteilung

Hirundigenin can easily be converted into anhydrohirundigenin by thermal dehydration. Both substances are stable to alkali but unstable under acid conditions. Dehydrogenation of anhydrohirundigenin, using selenium at 310°, gave a mixture of 2-methylphenanthrene ( 29 ), 1, 2-dimethyl-phenanthro [1,2-b] furan ( 30 ) and 1-ethyl-2-methyl-phenanthro [1,2-b] furan ( 32 ), all of which could be isolated in crystalline form. The last two substances are new and their structures were confirmed by synthesis. Through these results, as well as by further reactions and spectra, it could be shown that hirundigenin and anhydrohirundigenin are 16-methyl-15-oxapregnane derivatives, further, that they have two epoxide rings and that they probably have the structures 7 and 11. These structures were proved by O. Kennard et. al. through X-ray studies of p-bromobenzoyl-anhydrohirundigenin ( 13 ). As far as we know, 15-oxasteroids had not yet been found in nature.     

Die Cardenolide der Samen von Mansonia altissima A. CHEV. 2. Mitteilung Die Struktur von Mansonin und Strophothevosid Glykoside und Aglykone, 287. Mitteilung

Mansonin is the 2,3-di-O-methyl-6-deoxy-β-D-glucopyranoside of strophanthidin, and strophothevoside the corresponding 3-O-methyl-6-deoxy-β-D-glucopyranoside.     

Die Konstitution von Roridin D. Verrucarine und Roridine, 12. Mitteilung

The antibiotic roridin D (C₂₉H₃₈O₉), a companion of roridin A, yields on base catalysed hydrolysis verrucarol ( 3 ) and the hitherto unknown 2, 3-epoxy-2-anhydrororidinic acid ( 4 ) (C₁₄H₁₈O₇). Roridin D is a macrocyclic diester to which structure 1 is assigned. In roridin D an epoxy group replaces the hydroxyl group of roridin A.     

Die optische Umwandlung von dl-Magnoflorin bei der Papierchromatographie

Ohne Zusammenfassung     

Die Struktur von Corchorosid B. Glycoside und Aglykone, 329. Mitteilung

Corchoroside B has the empirical formula C₂₉H₄₂O₈ and was found to be a L -rhammoside of canarigenin ( 5 ), most probably the α, L-rhamnopyranoside ( 1 ).     

Die Synthese von 6-substituierten 2-Norbornanolen. Norbornane, 7. Mitteilung

The Synthesis of 6-substituted 2-Norbornanols The preparation of several 6-exo- and 6-endo-substituted 2-exo- and 2-endó-norbornanols and their p-toluenesulfonates is described.     

Die Struktur der Drevogenine. 2. Mitteilung Struktur von Drevogenin P. Glykoside und Aglykone, 278. Mitteilung

Drevogenin A was converted in several steps (acetylation, hydrogenation, dehydration, hydrogenation, the haloform reaction and energetic alkaline hydrolysis) into 3β, 11α, 12β-trihydroxy-5α-etianic acid, which could be characterised by its crystalline methyl ester ( 15 ) and its tri-O-acetyl methyl ester ( 16 ). The same acid was obtained by partial synthesis starting from hecogenin. Taking into consideration earlier results [1], the structure of drevogenin P is proved to be 3β, 11α, 12β, 14β-tetrahydroxy-20-oxo-Δ⁵-pregnene ( 7 ). Energetic hydrolysis of dihydro-3-O-acetyldrevogenin A gave a mixture of 17αH- and 17βH-desacyl-kondurangogenin A, which were obtained in crystalline form after separation by chromatography. The only difference between the basic structures of the drevogenins and kondurangogenin A is the presence of a double bond in the 5-position in the former.