Mass spectra of some (Z)-α-Phenyl-β-(2-thienyl)acrylonitriles

The mass spectra of some (Z)α-(4-R′-phenyl)-β-(2-thienyl-5-R)acrylonitriles (R = H, CH₃, Br; R′ = H, CH₃O, CH₃, Cl, NO₂) at 70 eV are reported. Mass spectra exhibit pronounced molecular ions. The compound's where R = H, and CH₃ are characterized by the occurrence of a strong [M - H]⁺ peak. Moreover, in all the compounds a m/z 177 peak occurs. In the compounds where R = H, [M - HS]* and [M - CHS]* ions are present except the nitroderivatives. Where R = CH₃, [M - HS]⁺ ion occurs.     

Synthesis and structure of ethyl (Z)-α-formylamino-β-arylacrylates

Ethyl (Z)-α-formylamino-β-arylacrylates were obtained in good yields by the condensation of ethyl N, N-diformylamino acetate and aromatic aldehydes in the presence of sodium ethoxide in ethanol. The structure of ethyl α-formylaminocinnamate was characterized by single crystal X-ray diffraction measurement.     

Syntheses and Absolute Configuration of (E)- and (Z)-α-Bisabolenes

Stereospecific syntheses of (E)- and (Z)-α-bisabolenes have made revision of the configuration of natural (+)-α-bisabolene from Opoponax oil necessary. ¹³C-NMR. spectroscopy has been used for the differentiation of these isomers.     

Die photochemische synthese von μ-(1-2-η:2-3-η-allen)-octacarbonyldimangan(0)

Novel dihydroiridium(III) complexes containing mono- and bi-dentate sulfur ligands have been isolated. The cationic complexes [Ir(COD)L₂]ClO₄ (COD = 1,5-cyclooctadiene, L = tetrahydrothiophene (tht) or trimethylene sulfide (tms); L₂ = (CH₃S)₂(CH₂)₃ (dth)), [Ir(COD)(L-L)]₂(ClO₄)₂ (L-L = 1,4-dithiacyclohexane (dt) or (t-BuS)₂(CH₂)₂ (tmdto)) and [Ir(CO)₂(tmdto)]₂-(ClO₄)₂ react with H₂ to give the corresponding iridium(III) dihydrides: [IrH₂COD)L₂]ClO₄ (Ia: L = tht, Ib: L = tms, Ic: L₂ = dth), [IrH₂(COD)-(L-L)]₂(ClO₄)₂ (IIa: L-L = tmdto, IIb: L-L = dt) and [IrH₂(CO)₂(tmdto)]₂-(ClO₄)₂ (III). The ¹H NMR chemical shifts and ν(IrH) data are discussed.     

Synthese von rac-threo und rac-erythro-α-(2, 2-Dichloracetamido)-β-hydroxy-p-nitrohydrozimtaldehyd

rac-threo-α-(2, 2-Dichloroacetamido)-β-hydroxy-p-nitrohydrocinnamaldehyde (3) and rac-erythro-α-(2, 2-dichloroacetamido)-β-hydroxy-p-nitrohydrocinnamaldehyde (4) were synthesized starting from α-acetamido-p-nitroacetophenone (7) , and their structures were proved b^n? reduction to rac-chloramphenicol (19) and rac-erythro-2-(2, 2-dichloroacetamido)-1-(p-nitrophenyl)^v 1, 3-propanediol (14) respectively. 3 exhibited only low antibacterial activity compared to rac-chloramphenicol (19) .     

A PMR conformational study of some (E)-α-nitro-β-arylstyrenes

The 60 MHz room temperature pmr data of some α-nitro-β-arylstyrenes are used to assign the stereochemical configuration. The variable temperature pmr spectra exclude the presence of a rotational isomerism. The preferred conformation are then established by analysis of the chemical shifts of the heterocyclic protons.     

Synthesis of (E)-5-oxo-2-(3-α and 3β-hydroxy-1-octenyl)-1-(4-N-pyrrolidine-2-butynyl)pyrrolidine

The synthesis of an oxotremorine analog, (E-5-oxo-2-(3α and 3β-hydroxy-1-octenyl)-1-(4-N-pyrrolidino-2-butynyl)pyrrolidine, is reported.     

Synthesis of propyl O-(α-L-rhamnopyranosyl)-(1→3)-[2,4-di-O-(2s-methylbutyryl)-α-L-rhamnopyranosyl]-(1→2)=(3-O-acetyl-β-D-glucopyranosyl)-(1→2)-βp-D-fucopyranoside,the tetrasaccharide moiety of Tricolorin A

Propyl O-(α-L-rhamnopyranosyl)-(1→3)-[2,4di-O-(2s-methylbutyryl)-α-L-rhamnopyranosyl]-(1→2)-(3-O-acetyl-β-glucopyranosyl)-(1→2)-β-D-fucopyranoside (1), the tetrasaccharide moiety of Ricolorin A, was synthesized in total 23 steps with a longest linear sequence of 10 steps, and overall yield of 3.7% from D-Glucose. The isomerization of the dioxolane-type benzylidene in the prance of NIS/AgOTf was observed. Tetrasaccharide 1 exhibited no activity against the cultured P388 cell as Tricolorin A did.     

A Stereospecific Synthesis of (E,Z)-α, β-γ, δ-Diunsaturated Aldehydes,Ketones, and Esters Using the Benary Reaction

The reaction between (Z)-1-alkenyllithium and (E)-β-(N, N-dialkylamino)-α, β-alkenals, (E)-β-(N, N-dialkylamino)-α, β-alkenones or (E)-β-(N, N-dialkylamino)-α, β-alkenoic esters yields mainly (E, Z)-α, β-γ, δ-diunsaturated aldehydes, ketones, or esters and is therefore highly stereospecific.     

Studies on furan derivatives IV. A simple preparation of α-substituted β-(5-nitro-2-furyl)ethynyls from α-substituted β-(5-nitro-2-furyl)vinylamines

α-Substituted β-(5-nitro-2-furyl)ethynyls were conveniently prepared by the deamination of α-substituted β-(5-nitro-2-furyl)vinylamines. Also the application of this reaction toward α,β-bis(p-nitrophenyl)vinylamine was examined and afforded α,β-bis(p-nitrophenyl)ethynyl as the main product.