Showing papers on "Bicyclic molecule published in 1988"

An efficient and catalytically enantioselective route to (S)-(−)-phenyloxirane

Abstract: Reduction de la chloro-2 acetophenone en presence de diphenyl-5,5 trimethylene-3,4 oxazaborolidine-1,3,2 suivie de dechlorhydratation

A samarium(II) iodide promoted tandem radical cyclization. The total synthesis of (.+-.)-hypnophilin and the formal synthesis of (.+-.)-coriolin

Abstract: Synthese des triquinones oxygenes du titre a partir de la methyl-6a tetrahydro-3,3a,6a cyclopenta [b] furannone-2

In situ cuprate formation via transmetalation between vinylstannanes and higher order cyanocuprates

Abstract: Addition conjuguee de vinyl stannanes a des enones, par l'intermediaire d'une transmetallation avec le (cyano dimethyl) cuivre-dilithium. Cette methode est tres generale et a ete appliquee avec succes dans la synthese de prostaglandines

Stereoselective cyclization of enynes mediated by metallocene reagents

Abstract: Les enynes-1,6 et -1,7 sont efficacement cyclisees en metallacyclopentenes bicycliques avec Cp 2 TiCl 2 /PMePh 2 /Na(Hg), Cp 2 ZrCl 2 /Mg(Hg) et Cp 2 ZCl 2 /2BuLi. Ces metallacycles sont hydrolyses en alkylidenecyclanes ou peuvent subir une reaction de metathese avec S 2 Cl 2 , Se 2 Cl 2 ou Ph 2 SnCl 2 pour donner des heterocycles

Five-membered aromatic heterocycles as dienophiles in Diels-Alder reactions. Furan, pyrrole, and indole

Abstract: Additions Diels Alder du butadiene-1,3 et de l'isoprene: obtention de derives de benzofuranne, indole et carbazole; effets des substituants

Novel synthesis of isoflavones by the palladium-catalyzed cross-coupling reaction of 3-bromochromones with arylboronic acids or its esters.

Abstract: The synthesis of isoflavone derivatives by means of palladium-catalyzed cross-coupling reaction between 3-bromochromones and arylboronic acids or its butyl esters is described.

Synthesis and reactions of iodo lactams

Abstract: Synthese d'iodo lactames par cyclisation a partir d'amides d'acides alcenoiques, du trifluoro methanesulfonate de trimethylsilyle et d'iode; les reactions nucleophiles et de solvolyse (catalysee par l'argent) sur ces composes se font souvent avec retention de configuration

Synthesis of condensed heteroaromatic compounds using palladium-catalyzed reaction

Abstract: Article de synthese traitant de la synthese catalysee par le palladium complexe ou Pd II (OAc) 2 d'intermediaires heterocycliques tels que des indoles, quinoleines, isoquinoleines et d'autres heterocycles oxygene- ou soufre azote

Synthesis and antiherpetic activity of (+/-)-9-[[(Z)-2-(hydroxymethyl)cyclopropyl]methyl]guanine and related compounds.

Abstract: A series of analogues of acyclovir and ganciclovir were prepared in which conformational constraints were imposed by incorporation of a cyclopropane ring or unsaturation into the side chain. In addition, several related base-modified compounds were synthesized. These acyclonucleosides were evaluated for enzymatic phosphorylation and DNA polymerase inhibition in a staggered assay and for inhibitory activity against herpes simplex virus types 1 and 2 in vitro. Certain of the guanine or 8-azaguanine derivatives were good substrates for the viral thymidine kinase and were further converted to triphosphate, but none was a potent inhibitor of the viral DNA polymerase. Nevertheless, one member of this group, (+/-)-9-[[(Z)-2-(hydroxymethyl)cyclopropyl]methyl]guanine (3a), displayed significant antiherpetic activity in vitro, superior to that of the corresponding cis olefin 4a. Another group, typified by (+/-)-9-[[(E)-2-(hydroxymethyl)cyclopropyl]methyl]adenine (17b), possessed modest antiviral activity despite an apparent inability to be enzymatically phosphorylated. The relationship of side-chain conformation and flexibility to biological activity in this series is discussed.

Pyrazolo[3,4-b]pyridines: Syntheses, reactions, and nuclear magnetic resonance spectra

Abstract: Efficient syntheses of approximately 70 simple substituted representatives of pyrazolo[3,4-b]pyridine 1 are reported from the following: (a) suitably substituted pyridines onto which a pyrazole rin...

Cyclopentane Synthesis via Free-Radical-Mediated Addition of Functionalized Alkenes to Substituted Vinylcyclopropanes

Abstract: Nouvelle strategie de synthese de cyclopentanes fonctionnalises grâce a l'addition catalysee par un radical phenylthiyle d'alcenes substitues sur des cyclopropanes vinyliques substitues

Triply convergent synthesis of (-)-prostaglandin E2 methyl ester

Abstract: Synthese de l'ester methylique de la prostaglandine PGE2 a partir du cyclopentadiene via une dihydroxy-4,5 cyclopentene-2one

A highly stereocontrolled, four-step synthesis of (.+-.)-lasubine II

Abstract: Synthese a partir de R-MgBr, Z-Cl et methoxy-4 pyridine (Z=benzyloxycarbonyl et R=dimethoxy-3,4 phenyl) via la Z-1 R-2 dihydro-2,3 1H-pyridone-4 et la chloro-4' butyl-2 Z-1 R-6 piperidone-4

Synthesis and Characterisation of the Sodium and Lithium Cryptates of Macrobicyclic Ligands incorporating pyridine, bipyridine, and biisoquinoline units

Abstract: Sythetic procedures have been deweloped for the preparation of sodium and lithium cryptates of the macrabicyclic ligands 1–11 containing pyridine, bipyridine, and biisoquinoline groups. They involve stepwise construction of the bicyclic system as will as direct macrobicyclisation procedures (Scheme 1) and give access to both symmetrical and dissymmetrical structures. Marked cation template effects have been found that facilitate the cyclisation processes. The ligands 1–11 were isolated as their cryptates with Na+ or Li+ cations.

Hexagonal lattice hosts for urea. A new series of designed heterocyclic receptors

Abstract: Synthese d'un derive octacyclique de naphtyridine-1,8, compose hote de l'uree a partir de benzylidene-5 butyl-9 octahydro acridone-4