Showing papers on "Bicyclic molecule published in 1982"

Derivatives of cis, endo-2-azabicyclo-(3.3.0)-octane-3-carboxylic acid, process for their preparation, medicines containing them and their use

Abstract: of the disclosure: Compounds of the formula I (I) in which the carboxyl group on carbon atom 3 is orienta-ted in the endo-position relative to the bicyclic ring system of cis-configuration, and in which R1 denotes hydro-gen, allyl, vinyl or a side-chain of a naturally occurring ?-aminoacid, which may be protected, R2 denotes hydrogen, alkyl, alkenyl or aralkyl, Y denotes hydrogen or hydroxyl and Z denotes hydrogen, or Y and Z together denote oxygen, and X denotes alkyl, alkenyl or cycloalkyl, or aryl which is optionally mono-, di- or tri-substituted by alkyl, alkoxy, hydroxyl, halogen, nitro, amino, alkylamino, di-alkylamino or methylenedioxy, or denotes indol-3-yl, a process for their preparation, agents containing these com-pounds and their use. Compounds of the formula I have a long-lasting intense hypotensive action.

Epoxidation of cyclic alkenes by bis(acetonitrile)chloronitropalladium(II): on the role of heterometallacyclopentanes and .beta.-hydrogen elimination in the catalytic oxidation of alkenes

Abstract: Reaction of the palladium complex with norbornene in acetone leads to the quantitative formation of the metallacycle, which can be isolated as a yellow solid. Decomposition of this metallatricycle under nitrogen in toluene solution produces exo-epoxynorbornene (ca 90% yield) at an initial rate of 3%/h. Part of this stability and change in product selectivity is attributed to the allycyclic bridgeheads. Intrametallacyclic ..beta..-hydrogen is restricted by the rotational rigidity of the bicyclic norbornane skeleton and by the attendant reintroduction of ring strain. 1 table.

Carbamate and carbonate salts of tertiary amines

Abstract: Novel carbamic and carbonic acid derivatives are provided by simultaneous reaction of a secondary amine and a tertiary amine with carbon dioxide. These derivatives correspond in general to the formula ##STR1## in which R 1 and R 2 may be individual substituents attached to the N or together form with N a heterocyclic moiety; R 3 , R 4 , R 5 may be individual short chain alkyl or hydroxyalkyl substituents on the N or form therewith a monocyclic or bicyclic heterocyclic moiety. These described compounds find particular use as heat activatable delayed action catalysts especially for use in polyurethane formulations.

Stereochemical Applications of Nmr Studies in Rigid Bicyclic Systems

Abstract: Introduction Aids to Making NMR Spectral Assignments in Rigid Bicyclic Systems Stereochemical Applications of NMR Chemical Shifts in Rigid Bicyclic Systems Stereochemical Applications on NMR Spin-Spin Coupling Constants in Rigid Bicyclic Systems.

Radioimmunologic determination of 15-keto-13,14-dihydro-PGE2: a method for its stable degradation product, 11-deoxy-15-keto-13,14-dihydro-11 beta, 16 xi-cyclo-PGE2.

Abstract: Publisher Summary This chapter describes the chemical instability of 15-keto- 13,14-dihydro-PGE2 under various conditions, the development of a radioimmunoassay (RIA)for the stable bicyclic degradation product, and conditions for the induced quantitative conversion of 15-ketodihydro-PGE2 in biological samples into this product prior to measurements. 15-ketodihydro-PGA2 undergo a different fate cyclization into a bicyclic product, l l-deoxy-15-keto-13,14-dihydro- 1 lβ,16ξ-cyclo-PGE2. This cyclization product contains at least two epimeric sites, at C-8 and C-16; furthermore, the cyclization of the PGA2 derivative might also involve a transient formation of the corresponding PGC2 compound, resulting in additional epimeric sites at C-11 and C-12. The radioimmunoassay described in this chapter is developed using a racemic mixture of these epimers for the preparation of the immunogen. The crucial point RIA is the prior quantitative conversion of all 15-ketodihydro-PGE2 present in the sample into the bicyclic derivative before analysis.

Cycloadditionsreaktionen von Allenyl-Kationen mit Cyclopentadien

Abstract: Propargylhalogenide R1 C C CR2R3X (14) und Cyclopentadien reagieren in Gegenwart von Zinkhalogeniden in Ether/Dichlormethan unter Bildung von 3-Halogenbicyclo[3.2.1]octa-2,6-dienen 13 (R1 = Alkyl) oder 5-(α-Halogenbenzyliden)norbornenen 15 (R1 = Aryl). Die Reaktionen werden durch stufenweise [3 + 4]- bzw. [2 + 4]-Cycloadditionen intermediarer Allenyl-Kationen 1 erklart, wobei die Propargylcyclopentenyl-Kationen 5 sowie die bicyclischen Vinyl-Kationen 9 oder 12 als Zwischenstufen durchlaufen werden. Initiiert man diese Reaktionen durch aquimolare Mengen Silbertrifluoracetat, lassen sich Abfangprodukte aller postulierten Zwischenstufen isolieren. Die relativen Energieinhalte der intermediaren Carbenium-Ionen werden mit Hilfe von Kraftfeldrechnungen unter Verwendung von Gasphasenstabilitaten einfacher Carbokationen ermittelt. Stereochemische Untersuchungen zeigen, das die Additionsreaktionen den kompakten Ubergangszustand 42 gegenuber 41 bevorzugen. Bei der Umsetzung des Propargylchlorids 14e mit Cyclopentadien erhalt man unter Zinkchloridkatalyse auser dem 1:1-Produkt 15e noch ein pentacyclisches 2:1-Produkt 17, das durch Rontgenstrukturanalyse aufgeklart wurde. Seine Bildung last sich durch [2 + 2]-Cycloaddition eines Allenyl-Kations mit Cyclopentadien erklaren. Cycloaddition Reactions of Allenyl Cations with Cyclopentadiene Propargyl halides R1 C+C CR2R3X (14) and cyclopentadiene react with zinc halide catalysis in ether/dichloromethane solution to give 3-halogenobicyclo[3.2.1]octa-2,6-dienes 13 (R1 = alkyl) or 5-(α-halogenobenzylidene)norbornenes 15 (R1 = aryl). The reactions are interpreted by stepwise [3 + 4]- and [2 + 4]-cycloadditions of intermediate allenyl cations 1, proceeding via propargylcyclopentenyl cations 5 and bicyclic vinyl cations 9 or 12. If the reactions are initiated by equimolar amounts of silver trifluoroacetate, quenching products of all postulated intermediates are isolated. The relative energies of the intermediate carbenium ions are estimated on the basis of force field calculations and of gas phase stabilities of simple carbocations. Stereochemical studies indicate that the addition reactions proceed via the compact transition state 42 rather than 41. The zinc chloride catalysed reaction of propargyl chloride 14e with cyclopentadiene yields the 2:1 product 17 (structurally assigned by X ray analysis) in addition to the 1:1 product 15e. The formation of 17 is rationalised by a [2 + 2]-cycloaddition of allenyl 1 with cyclopentadiene.

Synthese von 3‐Oxo‐8‐oxabicyclo[3.2.1]oct‐6‐en‐2‐carbonitrilen aus γ‐Brom‐β‐oxonitrilen und Furan via [4 + 3]‐Cycloaddition von 1‐Cyanallylium‐2‐olaten

Abstract: Verschiedene γ-Brom-β-oxonitrile 3 reagieren in Gegenwart von Silberoxid mit Furan stereoselektiv zu den Titelverbindungen 7. Befriedigende Ausbeuten werden nur mit solchen Bromiden 3 erhalten, deren γ-Kohlenstoff tertiar ist oder die sowohl am α- als auch γ-Kohlenstoff monoalkyliert sind (3c, e–h). Die Befunde werden durch eine [4 + 3]-Cycloaddition von intermediaren 1-Cyanallylium-2-olaten (14) an das 1,3-Dien-System des Furans erklart. Mit cyclischen γ-Brom-β-oxonitrilen (6) wurden zwei Typen von Cycloaddukten beobachtet: 3-Brom-3-methyl-2-oxocyclohexancarbonitril (6b) und 3-Brom-2-oxocyclododecancarbonitril (6d) reagieren zu den tricyclischen [4 + 3]-Cycloaddukten 10b und d, Analoga der Bicyclen 7. Bei 3-Brom-2-oxocyclohexancarbonitril (6a) und 3-Brom-5-tert-butyl-2-oxocyclohexancarbonitril (6e) wurde jedoch der Carbonyl-Sauerstoff mit einem α-Kohlenstoffatom des Furans verknupft, wobei die tricyclischen [3 + 2]-Cycloaddukte 12Aa und Ae entstanden. Die Struktur von endo-2,endo-4-Dimetyl-3-oxo-8-oxabicyclo[3.2.1]oct-6-en-exo-2-carbonitril (7eα) wurde durch eine Rontgenstrukturanalyse bestimmt. Synthesis of 3-Oxo-8-oxabicyclo[3.2.1]oct-6-ene-2-carbonitriles from γ-Bromo-β-oxonitriles and Furan via [4 + 3] Cycloaddition of 1-Cyanoallylium-2-olates Some γ-bromo-β-oxonitriles 3 react with furan in the presence of silver oxide to form stereoselectively the title compounds 7. Satisfying yields are obtained only with those bromides 3, whose γ-carbon ist tertiary or which are monoalkylated both at the α- and γ-carbon atoms. The results are explained by a [4 + 3] cycloaddition of 1-cyanoallylium-2-olate intermediates (14) to the 1,3-diene system of the furan. With cyclic γ-bromo-β-oxonitriles (6) two types of cycloadducts were observed: 3-bromo-3-methyl-2-oxocyclohexanecarbonitrile (6b) and 3-bromo-2-oxocyclododecanecarbonitrile (6d) form the tricyclic [4 + 3] cycloadducts 10b and d, analogs of the bicyclic adducts 7. With 3-bromo-2-oxocyclohexanecarbonitrile (6a) and 3-bromo-5-tert-butyl-2-oxocyclohexanecarbonitrile (6e), however, the carbonyl oxygen is connected with an α-carbon of the furan to give the tricyclic [3 + 2] cycloadducts 12Aa and Ae. The structure of endo-2,endo-4-dimethyl-3-oxo-8-oxabicyclo[3.2.1]oct-6-ene-exo-2-carbonitrile (7eα) was determined by X-ray analysis.

Bicyclic pyrimidin-5-one derivatives

Abstract: Novel 5H-thiazolo- and 5H-1,3,4-thiadiazolo[3,2-a]pyrimidin-5-one and 3,4-dihydro-2H,6H-pyrimido[2,1-b] [1,3]-thiazin-6-one derivatives, which compounds are useful psychotropic agents.

Five-membered ring annulation via thermal rearrangement of β-cyclopropyl α,β-unsaturated ketones. A formal total synthesis of the sesquiterpenoid (±)-zizaene

Abstract: Treatment of the β-iodo enones 7–10 with lithium (phenylthio)(cyclopropyl)cuprate provided excellent yields of the corresponding β-cyclopropyl α,β-unsaturated ketones 11–14, respectively. When 3-isopropenyl-2-cyclohexen-1-one (16) was allowed to react with dimethyloxosulfonium methylide in dimethyl sulfoxide – tetrahydrofuran, 3-(1-methylcyclopropyl)-2-cyclohexen-1-one (17) was produced in 59% yield. Although thermal rearrangement (~425–450 °C) of compounds 11 and 17 produced high yields of the annulation products 19 and 22, respectively, similar reactions involving the β-cyclopropyl enones 12 and 13 were not efficient in terms of production of the corresponding bicyclic systems (23, 26, and/or 27, respectively). In these cases, predominant (24 + 25 from 12) or significant (28 + 29 from 13) amounts of monocyclic dienones were formed. The annulation product 22 served as a convenient starting material for a new formal total synthesis of the sesquiterpenoid (±)-zizaene (30). Conjugate addition of lithium div...

Derivatives of bicyclic amino acids, process for their preparation, agents containing them and their use, as well as bicyclic amino acids as intermediates, and process for preparing them

Abstract: Die Erfindung betrifft cis, exo- und trans-Verbindungen der Formel I The invention relates to cis, trans-exo and compounds of formula I in der n = 0, 1 oder 2, - R 1 = Wasserstoff, gegebenenfalls durch Amino, Acylamino oder Benzoylamino substituiertes Alkyl, Alkenyl, Cycloalkyl, Cycloalkenyl, Cycloalkylalkyl, Aryl oder teilhydriertes Aryl, das jeweils durch Alkyl, Alkoxy oder Halogen substituiert sein kann, wie vorstehend im Aryi-Rest substituiertes Aralkyl, einen mono- bzw. bicyclischen Schwefel- oder Sauerstoff- und/oder Stickstoff-Heterocyclenrest oder eine Seitenkette einer naturlich vorkommenden Aminosaure, R 2 = Wasserstoff, Alkyl, Alkenyl oder Aralkyl, Y = Wasserstoff oder Hydroxy, Z = Wasserstoff oder Y und Z = zusammen Sauerstoff und X = Alkyl, Alkenyl, Cycloalkyl, durch (C 1 -C 4 )-Alkyl, (C 1 -C 4 )-Alkoxy, Hydroxy, Halogen, Nitro, Amino. in which n = 0, 1 or 2, - R 1 = hydrogen, optionally substituted by amino, acylamino or benzoylamino substituted alkyl, alkenyl, cycloalkyl, cycloalkenyl, cycloalkylalkyl, aryl or partially hydrogenated aryl, which may each be substituted by alkyl, alkoxy or halogen as above substituted in Aryi-aralkyl radical, a mono- or bicyclic sulfur or oxygen and / or nitrogen-heterocyclic residue, or a side chain of a naturally occurring amino acid, R 2 = hydrogen, alkyl, alkenyl or aralkyl, Y is hydrogen or hydroxyl, Z denotes hydrogen or Y and Z together oxygen and X = alkyl, alkenyl, cycloalkyl, by (C 1 -C 4) -alkyl, (C 1 -C 4) alkoxy, hydroxy, halogen, nitro, amino. (C 1 -C 4 )-Alkylamino. (C 1 -C 4) alkylamino. Di-(C 1 -C 4 ) alkylamino oder Methylendioxy mono, di- oder trisubstituiertes Aryl, oder lndol-3-yl bedeuten, Verfahren zu ihrer Herstellung, diese enthaltende Mittel und deren Verwendung sowie neue bicyclische Aminosauren als Zwischenstufen und zu deren Herstellung. Di- (C 1 -C 4) alkylamino or methylenedioxy mono di-, or tri-substituted aryl, or indol-3-yl, processes for their preparation, agents containing them and their use as well as novel bicyclic amino acids useful as intermediates and to their preparation.

Bicyclic lactams as antihypertensives

Abstract: This invention relates to bicyclic lactams and derivatives thereof which are useful as converting enzyme inhibitors and as antihypertensives.

Synthesis of prostanoids with bicyclo[2.2.1]heptane, bicyclo[3.1.1]heptane and bicyclo[2.2.2]octane ring systems. Activities of 15-hydroxy epimers on human platelets

Abstract: A number of prostanoids with bicyclo[2.2.1]heptane, bicyclo[3.1.1]heptane, and bicyclo[2.2.2]octane ring systems have been prepared by routes which allow the introduction of the omega chain after the alpha chain. The introduction of a 16-p-halophenoxy substituent confers platelet aggregation activity on both 15 alpha- and 15 beta-hydroxy epimers. In the case of the pinane thromboxane ring system, the natural omega-chain compound is an inhibitor of aggregation, whereas the 16-p-fluorophenoxy analogue is a potent aggregation agent.