Tricyclic Framework Research Articles

Tripyl-convergent total synthesis of a homochiral benzoindane-fused prostacyclin analog

Benzoindane-fused prostacyclin analog 14 was prepared from homochiral ammonium salt 5 in 7 steps and 35% overall yield. Key include addition of “soft” aryllithium reagent 6b to 5 to afford 7 ; and addition of homochiral acetylide 9 to the vinyl sulfone moiety of chloride 8 (with subsequent in situ cyclization) to afford 10 , thereby rapidly assembling the tricyclic framework of 14 . Compound 14 was a weak inhibitor of collagen-induced platelet aggregation having an IC 50 = 2.5μM.

Solution Structure and Preferred Orientation of 3,7-Dichloro-10H-phenothiazine Dissolved in Nematic Liquid Crystal

Abstract 1H NMR spectrum of the title compound was measured in a nematic liquid crystal ZLI1167 and analyzed utilizing modified versions of the LAOCN program. Direct couplings obtained were interpreted on the basis of a folded structure of tricyclic framework. The results show that the dihedral angle between the two benzene rings is 153.1±2.0° and the angle of S···N–H is 170.9±6.7°. Hence a “H-intra” conformation is dominant in a mobile state dissolved in the nematic liquid crystal. The preferred orientation of this molecule in ZLI1167 is discussed by comparing the results with those of the dibromo analogue reported previously and by comparing the principal axes of the order tensor with those of the moment of inertia. The chlorine and bromine atoms are supposed to exert a special steric effect on the ordering of these molecules.

Solution Structure and Preferred Orientation of 3,7-Dibromo-10H-phenothiazine Dissolved in Nematic Liquid Crystal

Abstract The NMR spectrum of the title compound has been measured in nematic phase ZLI1167 and analyzed to obtain the direct couplings. The direct couplings were interpreted by assuming a folded structure of the tricyclic framework. The dihedral angle of the two phenyl rings is determined to be 149.1±2.5° and a value of 170±3° is obtained for the angle of S···N–H. The NH proton is concluded to occupy a “equatorial” position on the central ring in a boat form. The preferred orientation of the molecule in ZLI1167 is discussed by comparing the principal axes of order tensor with those of the moment of inertia.

Promising cyclization reactions to construct the ring systems of brevianamides A,B

An effective intramolecular Michael cyclization and intramolecular SN 2′ cyclization is described for constructing the tricyclic framework of the natural mycotoxins brevianamides A,B.

ChemInform Abstract: REACTION OF CEPHALOSPORIN 3′‐TRIPHENYLPHOSPHONIUM YLIDE. SYNTHESIS OF A NOVEL TRICYCLIC CEPHALOSPORIN

AbstractCephalosporin‐3‐triphenylphosphonium‐Ylide (I) werden mit Trifluoracetaldehyd, Glyoxal und Methylglyoxal umgesetzt.

REACTION OF CEPHALOSPORIN 3′-TRIPHENYLPHOSPHONIUM YLIDE. SYNTHESIS OF A NOVEL TRICYCLIC CEPHALOSPORIN

Abstract Reaction of cephalosporin 3′-triphenylphosphonium ylide with glyoxal gave a good yield of new cephalosporin derivative which possessed tricyclic framework bridged between the C-2 and C-3′ positions.

ChemInform Abstract: REACTIVITY BY RING STRAIN: SPIROCYCLOPROPYL ANNELATED TRICYCLIC FRAMEWORK BY ONE‐POT THREE‐STEP REACTIONS

Chemischer InformationsdienstVolume 14, Issue 2 Isocyclic Compounds ChemInform Abstract: REACTIVITY BY RING STRAIN: SPIROCYCLOPROPYL ANNELATED TRICYCLIC FRAMEWORK BY ONE-POT THREE-STEP REACTIONS D. SPITZNER, D. SPITZNERSearch for more papers by this authorA. ENGLER, A. ENGLERSearch for more papers by this authorT. LIESE, T. LIESESearch for more papers by this authorG. + SPLETTSTOESSER, G. + SPLETTSTOESSERSearch for more papers by this authorA. DE MEIJERE, A. DE MEIJERESearch for more papers by this author D. SPITZNER, D. SPITZNERSearch for more papers by this authorA. ENGLER, A. ENGLERSearch for more papers by this authorT. LIESE, T. LIESESearch for more papers by this authorG. + SPLETTSTOESSER, G. + SPLETTSTOESSERSearch for more papers by this authorA. DE MEIJERE, A. DE MEIJERESearch for more papers by this author First published: January 11, 1983 https://doi.org/10.1002/chin.198302135Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume14, Issue2January 11, 1983 RelatedInformation

Imino‐bridged heterocycles. I. A derivative of benzo[5,6]cyclohepta[1,2‐b]pyridin‐5,11‐imine

AbstractThe current interest in structures that contain a tricyclic framework with a nitrogen bridged central ring has prompted us to examine the synthesis of imino‐bridged benzocycloheptapyridines. Treatment of 5,6‐trans‐dibromobenzo[5,6]cyclohepta[1,2‐b]pyridin‐11‐one with anhydrous methyl amine in THF produced 6‐β‐bromo‐5,6‐dihydro‐11α‐hydroxy‐12‐methyl‐11H‐benzo[5,6]cyclohepta[1,2‐b]pyridin‐5,11‐imine, the first example of the desired bridged derivatives.

The rearrangement of a tricyclic C 8H 11+ alkyl carbocation into a primary cyclopropylcarbinyl cation

The first unambiguous observation of a “bisected” primary cyclopropylcarbinyl cation is reported. This cation was formed by ring contraction of a C 8 tricyclic framework. Although totally unexpected from a bond energy-steric strain standpoint, this observation underlines the large resonance stability associated uith “bisected” cyclopropylcarbinyl cations.

The structure of a silicon analog of the psychotropic drug perathiepin: 5,5-dimethyl-10-(4-methylpiperazinyl)-10,11-dihydro-5 H-dibenzo[ b, f]silepin hydrofumarate

The solid state structure of the hydrofumarate salt of 5,5-dimethyl-10-(4-methylpiperazinyl)-1O,11-dihydro-5 H-dibenzo[ b, f]silepin (II), a silicon analog of perathiepin (I) in which divalent sulfur is replaced by the (CH 3) 2Si moiety, has been determined by X-ray diffraction methods. The compound, C 25H 32N 2O 4Si, crystallizes in the orthorhombic space group, Pbc2 1 with a 9.304(2), b 23.010(7), c 11.599(3) Å; the structure was refined by full-matrix least-squares techniques to a conventional R of 0.039 for 1858 counter reflections. The structure consists of a network of hydrogen-bonded hydrofumarate anions and the protonated heterocyclic unit. The tricyclic framework of the cation adopts a folded boat conformation with a dihedral angle between benzo group planes of 151.2°. In contrast to related systems, the piperazinyl substituent which has the expected chair conformation occupies a pseudoaxial site on the ethano bridge. Structural parameters of the tricyclic framework of the title compound and related compounds are compared.

The crystal and molecular structure of anti-1,2,4,5-tetraphenyl-3,6-dicarbomethoxytricyclo[3.1.0.02,4]hexane

1,2,4,5-Tetraphenyl-3,6-dicarbornethoxytricyclo[3.1.0.02,4]hexane crystallizes in the monoclinic space group P21/c with a = 10.044(4), b = 9.500(2), c = 14.172(4) Å, β = 104.38(2)°, and Z = 2. Using 1032 unique reflections with I > 3σ(I), the structural data were refined by full matrix least-squares techniques to R = 0.038. The molecule was found to be in the anti-configuration. All bond lengths within the highly strained central tricyclic framework were equal within experimental error and average 1.531 Å.

The structure of 5,5-dimethyl-5,6,11,12-tetrahydro-5h-dibenzo[b,f]silocin

The structure of 5,5-dimethyl-5,6,11,12-tetrahydro-5H-dibenzo[b,f]silocin (I) has been determined from X-ray data collected by counter methods. I crystallizes in the orthorhombic space group Pbca with a = 15.577(4), b = 22.368(5) and c = 8.640(2) Å; observed and calculated densities (Z = 8) are 1.11 g cm −3. Anisotropic full-matrix least squares refinement of nonhydrogen atoms, with hydrogen atoms included at fixed ideal locations gave a conventional R-factor of 5.0%. This is the first crystal structure of the dibenzo[b,f]metallocin framework with a single heteroatom in the central ring. The tricyclic framework adopts a distorted boat conformation in the solid state in contrast to dibenzcyclooctadiene. The dihedral angle between the planes of the two halves of the tricyclic framework (the benzo groups with the two central ring atoms bonded to them) is 111.4°.

The structures of 5-methyl-5-phenyl-5 H-dibenzo[ b,f] silepin and its saturated analog

The structures of 5-methyl-5-phenyl-5 H-dibenzo[ b,f] silepin (I) and 5-methyl- 5-phenyl-1O,11-dihydro-5 H-dibenzo [ b,f] silepin (II) have been determined from three-dimensional X-ray data collected by counter methods. I crystallizes in the orthorhombic space group Pnam with a 7.596(3), b 18.102(5) and c 12.190(2) Å; observed and calculated densities ( Z = 4) are 1.17 and 1.18 g cm −3, respectively. II crystallizes in the monoclinic space group P2 1 c with a 11.115(3), b 7.920(3), c 20.765(5) Å and β 111.71(2)°; observed and calculated densities ( Z = 4) are 1.17 g cm −3. Anisotropic refinement of nonhydrogen atoms, with hydrogen atoms included at fixed ideal locations, gave conventional R-factors of 4.5% (I) and 5.0% (II). Compound I exhibits the boat conformation for the tricyclic framework and is located on a crystallographically required mirror plane. Com- pound II has the expected folded boat conformation. The torsion angle about the 10,11-bond is 0.0° for I, a crystallographic symmetry requirement, and 89.9° for II. Mean SiC bond distances are 1.863 Å(I) and 1.875 Å(II). The dihedral angles between the planar benzo groups are 129.7° (I) and 137.2° (II); introduc- tion of unsaturation at the 10,11-position decreases the dihedral angle in the tri- cyclic system, i.e., the tricyclic system is more bent.

Complexes of transition metals with Schiff bases and the factors influencing their redox properties. Part I. Nickel and copper complexes of some diketone bisthiosemicarbazones

A series of nickel complexes, containing a planar NiN2S2 co-ordination unit, where the ligand is a tricyclic tetradentate Schiff base derived from R1CO·COR2(R1= R2= H or Me; R1= H, R2= Me), cyclohexane-1,2-dione, camphorquinone, hexane-2,5-dione, hexene-2,5-dione and phthaladehyde and either thiosemicarbazide or 4-methylthiosemicarbazide {NH2·NH·C(:S)·NHMe}, have been prepared and characterised. Diacetylbis-(thiosemicarbazonato) copper(II), and its 3-ethoxybutane-1,2-dione bis-(4-methylthiosemicarbazonato) analogue, have also been prepared. A polarographic and cyclic voltammetric examination of these complexes has revealed that they undergo an ill defined, irreversible oxidation process, at ca.+1·0 V, but that they may be reduced in two, reversible, one-electron steps. The half-wave potentials for the reduction waves depend on the substituents attached to the periphery of the tricyclic ligand framework, on the central metal atom, and on the extent of the conjugation around the ligand. A macrocyclic complex, obtained by treatment of hexane-2,5-dione bis-(4-methylthiosemicarbazonato) nickel with αα′-o-dibromoxylene, has been prepared, and is believed to contain octahedrally co-ordinated nickel(II)(axial Br).