Synthetic experiments related to the indole alkaloids V. mercuric acetate oxidation of 2-[2-(3-indolyl)ethyl]-1,2,3,4-tetrahydroisoquinolines and the formation of benz[a]indolo[3,2-h]quinolizine derivatives

Oxidation of 2-[2-(3-indolyl)ethyl]-1,2,3,4-tetrahydroisoquinoline (I) with mercuric acetate gave 5,6,8,9,14,14b-hexahydrobenz[a]indolo[3,2-h]quinolizine (IV) and 8,9-dihydro-14H-benz[a]indolo[3,2-h]quinolizin-7-ium iodide (VI), as well as starting material. The base (IV) was oxidized with iodine and potassium acetate to VI and on Palladium carbon - maleic acid dehydrogenation yielded 5,6-dihydro-14H-benz[a]indolo[3,2-h]-quinolizin-7-ium iodide (IX), and 14H-benz[a]indolo[3,2-h]quinolizin-7-ium iodide (X). Heating the iodide (VI) with Palladium-carbon brought about an irreversible rearrangement to VII and both these salts with base yielded the red anhydro base 8, 9-dihydrobenz[a]indolo[3,2-h]quinolizine (VIII). This base was also obtained from IV by oxidation in air. The corresponding 8, 9-dehydroanhydro base (XI), benz[a]indolo[3,2-h]quinolizine, was readily obtained from X and alkali. The quinolizinium salts (VI), (VII), and (IX), on catalytic, zinc dust and acetic acid, or sodium borohydride reduction, regenerated the base (IV). Selenium degradation of IV gave, among other products, 1-(2-ethylphenyl)-β-carboline. An analogous series of products was obtained with the 6, 7-dimethoxy derivative of I. Various other aspects of these and related transformations are described.     

Beiträge zur Massenspektrometrie der Gelsemium-Alkaloide

Zusammenfassung Von den Nebenalkaloiden vonGelsemium sempervirens (L.) Ait. konnte eine Verbindung, zunächst als Gelsemium-Alkaloid A bezeichnet, in reiner Form dargestellt und ihre Konstitution als N-1-Methoxygelsemin aufgeklärt werden. Für die Strukturermittlung erwies sich die Massenspektrometrie als besonders wertvoll. Die Massenspektren einiger Gelsemiumalkaloide sind wiedergegeben, die Fragmentierung dieser Verbindungen wird diskutiert.Au\erdem wurde eine größere Anzahl neuer Basen in kleiner Menge nachgewiesen.

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Contributions to mass-spectrometry of gelsemium-alkaloids (The structure of gelsemium-alkaloid A)

From the minor alkaloids ofGelsemium sempervirens (L.) Ait., one compound, preliminary designated as Gelsemiumalkaloid A, could be isolated and was identified as N-1-Methoxy-gelsemine. For the structure-elucidation mass-spectrometry has been proven to be of great value. Mass spectra of some Gelsemium-alkaloids are reported and the fragmentation of these compounds is discussed.There were further detected a quantity of new alkaloids in small amounts.

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Mit 7 Abbildungen

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Anmerkung bei der Korrektur (23.10.1972): Während der Drucklegung dieser Arbeit erschien eine Publikation vonE. Wenkert u. Mitarb. [Exper.28, 377 (1972)], in der die Struktur des Gelsevirins als N-1-Methoxy-gelsemin angegeben wird; somit ist Gelsemium-Alkaloid A offensichtlich mit Gelsevirin identisch. Eine solche Identifizierung was uns nicht möglich, da einerseits kein authentisches Präparat von Dr.Marion verfügbar was (Brief von Dr.Edwards, Ottawa, vom 21.6.1971) und andrerseits die wenigen, bisher veröffentlichten Daten über Gelsevirin hierfür nicht ausreichen.     

Pyrido[2,3-d]pyrimidines,II. One step synthesis of pyrido[2,3-d]pyrimidines and pyrimido[4,5-b]quinolines from 6-amino uracils

Summary Reduction of 6-azidouracils2 with hydrogen palladium or sodium dithionite afforded the corresponding 6-aminouracils5 which could also be obtained by reaction of2 with triphenylphosphanevia phosphazenes and subsequent hydrolysis (Staudinger reaction). The use of trimethylphosphite instead of phosphanes yields with2b the expected trimethoxyphosphazene3c, whereas2a reacts to the phosphonoaminopyrimidine4. The syntheses of 5-hydroxy pyrido[2,3-d]pryimidine-2,4,7-triones6, pyrido[2,3-d]pyrimidine-2,4,5-triones8, cyclopenta[e]pyrido[2,3-d]pyrimidin-2,4,5-triones7a,c, and tetrahydro-pyrimido[4,5-b]quinolin-2,4,5-triones7b,d by condensation of 6-aminouracils5 with malonates, ethylaceto/benzoylacetate, ethyl 2-oxocyclopentanecarboxylate and ethyl 2-oxocyclohexanecarboxylate, respectively, are described.

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Pyrido[2,3-d]pyrimidine, 2. Mitt. Einstufige Synthese von Pyrido[2,3-d]pyrimidinen und Pyrimido[4,5-b]chinolinen aus 6-Aminouracilen

Zusammenfassung Reduktion der 6-Azidouracile2 mit Wasserstoff/Palladium oder Natriumdithionit ergibt die entsprechenden 6-Aminouracile5, die auch durch Reaktion von2 mit Triphenylphosphin und anschließende Hydrolyse erhalten werden können (Staudinger-Reaktion). Die Verwendung von Trimethylphosphit anstelle von von Trimethylphosphin ergibt mit2b das erwartete Trimethoxyphosphazin3c, während2a zum Phosphonoaminopyrimidin4 reagiert. Die Synthesen der 5-Hydroxy-pyrido[2,3-d]pyrimidin-2,4,7-trione6, der Pyrido[2,3-d]pyrimidin-2,4,5-trione8, der Cyclopenta[e]pyrido[2,3-d]pyrimidin-2,4,5-trione7a,c und der Tetrahydro-pyrimido[4,5-b]chinolin-2,4,5-trione7b,d durch Kondensation der 6-Aminouracile5 mit Malonat, Acetat, Ethyl-2-oxocyclopentancarboxylat und Ethylcyclohexancarboxylat werden beschrieben.

     

Alkylation of 6-(3-Indolyl)indolo[2,3-b]carbazole

The methylation and allylation of 6-(3-indolyl)indolo[2,3-b]carbazole were studied, and its trimethyl and mono-, di-, and triallyl derivatives were obtained.     

Synthesis of 2-aryl-6,6-dimethyl-8-oxo-5,6,7,8-tetrahydro-1,2,4-4H-triazolo[3,2-b]benzothiazoles and their 3-aryl-[3,4-b] isomers

Summary Condensation of 3-aryl-5-thio-1,2,4-4H-trizoles (2a–i) and 2-bromodimedone (3) inTHF/benzene gave 2-aryl-6,6-dimethyl-8-oxo-5a-hydroxy-5,5a,6,7,8,8a-hexahydro-1,2,4-4H-triazolo[3,2-b]benzothiazoles (5a–i). These were also obtained by a one step synthesis on heating a mixture of dimedone,NBS, and2a–i in benzene containing a trace of benzoyl peroxide. Thermal dehydration of5a–i inPPA/anhydrous ethanol yielded the corresponding 2-aryl-6,6-dimethyl-8-oxo-5,6,7,8-tetrahydro-1,2,4-4H-triazolo[3,2,b]benzothiazoles (6a–i). The formation of [3,4-b] fused isomers (4a–i) during the reaction of2 with3 was ruled out by an unambiguous synthesis of8a–i. Antibacterial screening of selected compounds againstEscherichia coli andStaphylococcus aureus was not encouraging.

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Synthese von 2-Aryl-6,6-dimethyl-8-oxo-5,6,7,8-tetrahydro-1,2,4-4H-triazolo[3,2-b]benzothiazolen und ihrer 3-Aryl-[3,4-b]-Isomeren

Zusammenfassung Die Kondensation von 3-Aryl-5-thio-1,2,4-4H-triazolen (2a–i) mit 2-Bromdimedon (3) inTHF/Benzol ergab 2-Aryl-6,6-dimethyl-8-oxo-5a-hydroxy-5,5a,6,7,8,8a-hexahydro-1,2,4,-4H-triazolo[3,2-b]benzothiazole (5a–i). Dasselbe Ergebnis wurde durch Erhitzen einer Mischung von Dimedon,NBS und2a–i in Benzol unter Zusatz einer Spur Benzoylperoxid in einer einstufigen Synthese erreicht. Thermische Dehydrierung von5a–i inPPA/Ethanol(abs.) ergab die entsprechenden 2-Aryl-6,6-dimethyl-8-oxo-5,6,7,8-tetrahydro-1,2,4-4H-triazolo[3,2-b]benzothiazole (6a–i). Die Bildung [3,4-b]-kondensierter Isomere (4a–i) während der Reaktion von2 mit3 konnte durch eine eindeutige Synthese von8a–i ausgeschlossen werden. Antibakterielles Screening ausgewählter Verbindungen gegenüberEscherichia coli undStaphylococcus aureus brachte keine ermutigenden Resultate.

     

3-Methyl[1,3,4]thiadiazino[2,3-b]quinazolin-6-ones

4H,6H-[1,3,4]Thiadiazino[2,3-b]quinazolin-6-one with a methyl group in position 3 (6a) has been synthesised by the condensation of 3-amino-2-mercapto-3H-quinazolin-4-one (1) with allyl bromide (2) followed by treatment with bromine and subsequent dehydrohalogenation of the brominated product (4) with ethanolic sodium hydroxide. Its isomeric 3-methyl-2H,6H-[1,3,4]thiadiazino[2,3-b]quinazolin-6-one (6b) has also been obtained by condensation of1 and bromoacetone (7) followed by cyclisation of the intermediates (8 or9) with hydrobromic acid or with concentrated sulphuric acid. The structures have been established on the basis of IR and PMR data.

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3-Methyl[1,3,4]thiadiazino[2,3-b]chinazolin-6-one

Zusammenfassung Zur Synthese von 4H,6H-[1,3,4]thiadiazino[2,3-b]chinazolin-6-on (6a) wurde die Kondensation von 3-Amino-2-mercapto-3H-chinazolin-4-on (1) mit Allylbromid mit nachfolgender Behandlung mit Brom und Dehydrohalogenierung des bromierten Produktes4 mit ethanolischer Natronlauge herangezogen. Das zu6a isomere 2H,6H-Produkt6b wurde ebenfalls durch Kondensation von1 mit Bromaceton und nachfolgender Cyclisierung der Zwischenprodukte8 bzw.9 mit HBr oder H₂SO₄ erhalten. Die Strukturen wurden mittels IR und NMR abgesichert.

     

DMF acetals as alkylating and cyclizing agents: A facile route to substituted pyrazolo[3,4-d]pyrimidine-4,6(5H,7H)-diones

Summary Several 7-methyl-5-alkyl-2-vinylpyrazolo[3,4-d]pyrimidine-4,6(5H,7H)-diones were prepared. The successful cyclization and alkylation of 6-(-methylbenzylidenehydrazino)-1-methyluracils2a–d using dimethylformamide acetals at high temperature provided6a–d,7a–d, and8a–d. Treatment of6a–d and7a–d with acid afforded 7-methyl-5-alkylpyrazolo[3,4-d]pyrimidine-4,6(5H,7H)-diones9a,b; under the same conditions,3a–d reacted to 7-methylpyrazolo[3,4-d]-pyrimidine-4,6(5H)-dione (4) in good yield.

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DMF-Acetale als Alkylierungs- und Ringschlußreagentien: ein einfacher Weg zu substituierten Pyrazolo[3,4-d]pyrimidin-4,6(5H,7H)-dionen

Zusammenfassung Es wurden verschiedene 7-Methyl-5-alkyl-2-vinylpyrazolo[3,4-d]pyrimidin-4,6(5H,7H)-dione hergestellt. Cyclisierung und Alkylierung der 6-(-Methylbenzylidenhydrazino)-1-methyl-uracile2a–d mit Hilfe von Dimethylformamidacetalen bei hohen Temperaturen ergab6a–d,7a–d und8a–d. Behandlung von6a–d und7a–d mit Säure lieferte die 7-Methyl-5-alkylpyrazolo[3,4-d]pyrimidin-4,6(5H,7H)-dione9a,b; unter den gleichen Bedingungen reagierten3a–d in guter Ausbeute zu 7-Methylpyrazolo[3,4-d]pyrimidin-4,6(5H)-dion (4).

     

Synthesis and reactions of 2-deoxy-β-D-ribofuranosyl derivatives of 3-aryl-4H-pyrrolo[2,3-d]pyrimidin-4-imines

Summary 3-Aryl-7-(2-deoxy--D-erythro-pentofuranosyl)-3,7-dihydro-4H-pyrrolo[2,3-d]-pyrimidin-4-imines (4) as well as 4-arylamino-7-(2-deoxy--D-erythro-pentofuranosyl)-2-methyl-5-phenyl-7H-pyrrolo[2,3-d]pyrimidines (7) have been synthesized by glycosylation of the sodium salt of the corresponding nucleobases with 2-deoxy-3,5-di-O-p-toluyl--D-erythro-pentofuranosyl chloride (2) followed by subsequent deprotection with sodium methoxide in methanol. The deprotected nucleoside4 undergoes aDimroth rearrangement on reflux for 24 h in water to furnish the 4-arylamino nucleoside7.

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Synthese und Reaktionen von 2-Deoxy--D-ribofuranosylderivaten von 3-Aryl-4H-pyrrolo[2,3-d]pyrimidin-4-iminen

Zusammenfassung 3-Aryl-7-(2-deoxy--D-erythro-pentafuranosyl)-3,7-dihydro-4H-pyrrolo[2,3-d]-pyrimidin-4-imine (4) und 4-Arylamino-7-(2-deoxy--D-erythro-pentofuranosyl)-2-methyl-5-phenyl-7H-pyrrolo[2,3,-d]pyrimidine (7) wurden durch Glycosylierung der Natriumsalze der entsprechenden Nucleosidbasen mit 2-Deoxy-3,5-di-O-p-toluyl--D-erythro-pentofuranosylchlorid (2) und anschließende Entfernung der Schutzgruppe mit Natriummethoxid in Methanol hergestellt. Das entschützte Nucleosid4 ergibt bei 24-stündigem Erhitzen in Wasser unter Rückfluß über eineDimroth-Umlagerung das 4-Aminonucleosid7.

     

Regioselective annelation of 3-(prop-2-ynylsulfanyl)-1,2,4-benzotriazine to thiazolo[2,3-c][1,2,4]benzotriazine

Summary Thiosemicarbazide reacted with 1,2-diaminobenzene to give 1,2-dihydro-3-thioxo-1,2,4-benzotriazine (1) in fairly good yield in a solvent free reaction under microwave irradiation.1 was condensed with prop-2ynyl bromide in the presence of sodium methoxide to afford the corresponding 3-(prop-2-ynylsulfanyl)-1,2,4-benzotriazine (5). Transformation of5 to 3-methylidene-2,3-dihydro-9H-thiazolo[2,3-c][1,2,4]benzotriazine (6) was performed in the presence of a palladium salt.

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Regioselektive Anellierung von 3-(prop-2-inylsulfanyl)-1,2,4-benzotriazin zu Thiazolo[2,3-c][1,2,4]benzotriazin

Zusammenfassung Thiosemicarbazid reagierte mit 1,2-Diaminobenzol ohne Lösungsmittel und unter Bestrahlung mit Mikrowellen in guter Ausbeute zu 1,2-Dihydro-3-thioxo-1,2,4-benzotriazin (1), welches in Gegenwart von Natriummethoxid mit Prop-2-inylbromid zum entsprechenden 3-(Prop-2-inylsulfanyl)-1,2,4-benzotriazin (5) kondensiert wurde. Die Umsetzung von5 zu Methyliden-2,3-dihydro-9H-thiazolo[2,3-c] [1,2,4]benzotriazin (6) gelang unter Palladiumkatalyse.

     

Condensed thiazoles,I: Synthesis of 5,7-disubstituted thiazolo[4,5-d]pyrimidines as possible anti-HIV,anticancer, and antimicrobial agents

Summary A convenient and simple synthesis of 5-mercapto-3-phenyl-2-thioxo-2,3-dihydrothiazolo-[4,5-d]pyrimidin-7(6H-one(2) and its 5,7-dichloro (3), 5,7-diazido (4), 5,7-diamino (5), 5,7-dimerapto (6), 5,7-dimethylthio (7), and 6-methyl-5-methylthio (8) derivatives is described. The prepared compounds were screened for theirin vitro anti-HIV, anticancer, antibacterial and antifungal activities.

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Kondensierte Thiazole, 1. Mitt.: Synthese von 5,7-disubstituierten Thiazolo[4,5-d]pyrimidinen als potentielle anti-HIV, anticancerogene und antimikrobielle Verbindungen

Zusammenfassung Die Synthese von 5-Mercapto-3-phenyl-2-thioxo-2,3-dihydrothiazolo[4,5-d-pyrimidin-7(6H)-on (2) und seiner 5,7-dichloro-(3), 5,7-diazido-(4), 5,7-dimanio-(5), 5,7-dimercapto-(6), 5,7-dimethylthio- (7) und 6-methyl-5-methylthio-Derivaten (8) wird beschrieben. Die hergestellten Verbindungen wurden auf ihrein vitro anti-HIV, anticancerogenen, antibakteriellen und antimykotischen Aktivitäten geprüft.

     

Synthesen von 4-Amino-thieno[2,3—b]pyridinen

The Cyclization of 2-(1,1-dicyanovinylamino)-thiophenes2 by treatment with AlCl₃ yield 4-amino-5-cyano-thieno[2,3-b]pyridines3. 2-(1-acylvinyl-amino)-3-cyano-thiophenes7, obtainable from 2-amino-3-cyano-thiophenes and -diketones, react in the presence of AlCl₃ to form 4-acylamino-thieno[2,3-b] pyridines8. This reaction is connected with the transfer of the acyl group from C- to the N-atom. 4-Amino-5-cyano-thieno[2,3-b]pyridones-(6)11 are synthesized from 2-amino-3-cyano-thiophenes and ethyl cyano acetate in the presence of sodium ethoxide.

     

Neue Derivate der 2-Acylamino-thiophen-(und-benzo[b]thiophen-)-3-carbonsäure sowie des ([1]Benzo-)Thieno[2,3-d]-pyrimidin-4(3H)-ons

The title substances1 and2 were prepared by acylation of the corresponding ethyl 2-amino-thiophene- (or:-4,5,6,7-tetrahydro-benzo[b]thiophene)-3-carboxylates, in some cases followed by reactions introducing a basic substituent.Additionally a group of 2-aroylamino-thiophene-(or:-4,5,6,7-tetrahydro-benzo[b]thiophene)-3-carboxamides was subjected to ring closure reactions, yielding the corresponding 2-aryl-thieno[2,3-d]pyrimidin-4(3H)-ones and 2-aryl-[1]benzothieno[2,3-d]pyrimidin-4(3H)-ones (both:3).

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Zum Teil unter Mitarbeit vonFerdinand Fuhrmann     

Beiträge zur Chemie schwefelhaltiger Heterocyclen, 6. Mitt.: Eine Umlagerungsreaktion des 6-Oxo-6H-benz[b]indeno[1,2-d]thiophens

Zusammenfassung Abweichend von der intramolekularenFriedel-Crafts-Reaktion des 3-Phenyl-benzo[b]thiophen-2-carbonsäurechlorids, welche zu 6-Oxo-6H-benz[b]indeno[1,2-d]thiophen (1) führte, lieferten Versuche zur direkten Cyclisierung der 3-Phenyl-benzo[b]-thiophen-2-carbonsäure mittels Polyphosphorsäure ein anderes Produkt. Dieses wurde als 6-Oxo-6H-anthra[1,9-bc]thiophen (2) identifiziert. Es konnte gezeigt werden, daß beim Erhitzen von1 mit Polyphosphorsäure eine Umlagerung zu2 auftritt.

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Contributions to the chemistry of sulfur-containing heterocycles, VI.: A rearrangement reaction of 6-oxo-6H-benzo[b]indeno[1,2-d]thiophene

In contrast to the intramolecularFriedel-Crafts reaction of 3-phenyl-benzo[b]thiophene-2-carbonyl chloride, leading to 6-oxo-6H-benz[b]indeno[1,2-d]thiophene (1), attempts to directly cyclize 3-phenyl-benzo-[b]thiophene-2-carboxylic acid by means ofPPA gave a different product. This was identified as 6-oxo-6H-anthra[1,9-bc]thiophene (2). It was shown that1 under-goes a rearrangement to2 when heated withPPA.

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Mit 2 Abbildungen

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Unserem sehr verehrten Lehrer, Herrn o. Prof. Dr.O. Hromatka, zum 65. Geburtstag gewidmet.

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5. Mitt.:F. Sauter, Mh. Chem.101, 535 (1970).     

Beiträge zur Chemie schwefelhaltiger Heterocyclen, 4. Mitt.: 6H-Benz[b]indeno[1,2-d]thiophen und 10H-Benz[b]indeno-[2,1-d]thiophen

Zusammenfassung Intramolekulare Cyclisierungsreaktionen von 3-Phenyl-benzo[b]thiophen-2-carbonsäurechlorid und von 2-Phenyl-benzo[b]thiophen-3-carbonsäurechlorid lieferten 6-Oxo-6H-benz[b]indeno[1,2-d]thiophen bzw. 10-Oxo-10H-benz[b]indeno[2,1-d]thiophen.

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Contributions to the chemistry of sulfur containing heterocycles, IV.: 6H-Benzo[b]indeno[1,2-d]thiophene and 10H-benzo-[b]indeno[1,2-d]thiophene

Intramolecular cyclization reactions of 3-phenyl-benzo[b]thiophene-2-carbonyl chloride and of 2-phenyl-benzo[b]-thiophene-3-carbonyl chloride gave 6-oxo-6H-benz[b]indeno-[1,2-d]thiophene and 10-oxo-10H-benz[b]indeno[2,1-d]thiophene, respectively.

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3. Mitt.:F. Sauter, Mh. Chem.99, 2100 (1968).     

Synthesis and reactions of 2,3-dimethylfuro[3,2-c]pyridines

Summary A number of substituted 2,3-dimethylfuro[3,2-c]pyridines was synthesized. 3-(4,5-Dimethyl-2-furyl)propenoic acid (1) was converted to the acid azide2, which in turn was cyclized to give 2,3-dimethyl-5H-furo[3,2-c]pyridine-4-one (3) by heating at 240°C in Dowtherm. The pyridone3 was chlorinated with phosphorus oxychloride to give4, which was reduced with zinc and acetic acid to 2,3-dimethylfuro[3,2-c]pyridine (5). Treatment of4 with several secondary heterocyclic amines led to compounds6a–6c. Reaction of pyridone3 with phosphorus pentasulfide rendered the thione7, which was methylated to8a. The 4-methoxy derivative8b was obtained from4 with sodium methoxide. 2,3,5-Trimethylfuro[3,2-c]pyridine-4-one (9) was obtained by reaction of3 with methyl iodide.Dedicated to Professor Dr.Fritz Sauter on the occasion of his 65th birthday     

Synthesis of Pyrrolo[a]- and Pyrrolo[c]phenanthridine Derivatives and Indolinyl and Indolylsubstituted 6-Phenanthridines

The corresponding Mannich bases have been synthesized by the aminomethylation of 6-methyl-1H-pyrrolo[2,3-a]- and 4-methyl-3H-pyrrolo[3,2-c]phenanthridinium iodides. The interaction of 6-chloro-phenanthridine with indoline and with 5-amino-N-acetylindoline gave the corresponding derivatives of phenanthridine. 6-(1-Indolyl)phenanthridine has been obtained by the dehydrogenation of 6-(1-indolinyl)phenanthridine with manganese dioxide.     

New hetero-annelation reactions using N-[bis-(methylthio)-methylene]-amino and related reagents

Summary Reaction of acyclic (B _1–3) and cyclic (R _4–5)BMMA (=N-[b is-(methylthio)-methylene]-amino) reagents withGewald-type thiophene derivatives (2,3) led to annelation of pyrimidine moieties. Thus, linear thiazolo- or thiazino- and pyrrolo-, pyrido- or azepino-fused thiopyrano[4,3:4,5]thieno-[2,3-d]pyrimidines (5 and6) as well as the angular imidazo-fused thiopyrano[4,3:4,5]thieno-[2,3-d]pyrimidine8 were easily obtained from one-pot reactions in good yields.on leave from Chemistry Department, Minia University, El-Minia, Egypt     

A second synthesis ofD-apio-β-D-furanosyl maleimide as a structural analogue of showdomycin

Summary Apioshowdomycin (3-(D-apio--D-furanosyl)-1H-pyrrole-2,5-dione,2) has been prepared as an analogue of the C-nucleoside showdomycin (1) in seven steps, starting from 2,3-O-isopropylidene-D-apio-D-furanose (8). The key step is the addition of a radical generated from apiosyl bromide5b to (E)-methyl 3-cyanoacrylate (4).

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Eine zweite Synthese vonD-Apio--D-furanosylmaleimid als Strukturanaloges von Showdomycin

Zusammenfassung Apioshowdomycin (3-(D-apio--D-furanosyl)-1H-pyrrol-2,5-dion,2) wurde als Analoges des C-Nucleosids Showdomycin (1), ausgehend von 2,3-O-Isopropyliden-D-apio-D-furanose (8), in sieben Stufen hergestellt. Der Schlüsselschritt ist die Addition eines aus dem Apiosylbromid5b generierten Radikals an (E)-Methyl-3-cyanoacrylat (4).

     

Annelation of drotaverine by <Emphasis Type="Italic">p</Emphasis>-quinones to form hydroxyindolo- and hydroxybenzindoloisoquinoline derivatives

1-(3, 4-Diethoxybenzyl)-6, 7-diethoxy-3, 4-dihydroisoquinoline (drotaverine, 1a) reacts with p-benzoquinone (2) and p-naphthoquinone (3) in nitromethane or during fusion to give 5-(3, 4-diethoxyphenyl)-7, 8-diethoxy-3-hydroxy-5a, 10, 11, 12-tetrahydroindolo[2, 1-a]isoquinoline (4) and 7-(3, 4-diethoxyphenyl)-9, 10-diethoxy-5-hydroxy-7a, 12, 13, 14-tetrahydrobenz[g]indolo[2, 1-a]isoquinoline (5), respectively. Compounds 4 and 5 are smoothly alkylated at the oxygen atom in the presence of bases. The structure of one alkylation product, viz., 3-allyloxy-5-(3, 4-diethoxyphenyl)-7, 8-diethoxy-5a, 10, 11, 12-tetrahydroindolo[2, 1-a]isoquinoline, was established by X-ray diffraction analysis.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 761–769, March, 2005.     

Reaction of 6-methyl-6-p-tolyl-4-ethoxy-5,6-dihydro-pyran-2-one1 with perchloric acid

6-Methyl-6-p-tolyl-4-ethoxy-5,6-dihydro-pyran-2-one (1) undergoes decarboxylative elimination with perchloric acid in ether to give 4-p-tolyl-3-penten-2-one (3), the structure of which has been confirmed through an unambiguous synthesis.

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Reaktion von 6-Methyl-6-p-tolyl-4-ethoxy-5, 6-dihydro-pyran-2-on mit PerchlorsäureKurze Mitteilung

Zusammenfassung Die Titelverbindung (1) ergibt mit Perchlorsäure unter decarboxylierender Eliminierung 4-p-Tolyl-3-penten-2-on (3). Die Struktur von3 wurde mittels eines eindeutigen Syntheseweges festgelegt.