Irradiation of substituted 2-benzylidenecyclopentanone O-alkyl and O-acetyloximes in methanol provides a convenient synthesis of alkyl, alkoxy, hydroxy, acetoxy, amino, dimethylamino and benzo substituted annulated quinolines. para-Substituents yield 6-substituted-2,3-dihydro-1H-cyclopenta[b]quinolines with 8-substituted products being obtained from ortho-substituted starting materials. Reactio...

A series of annulated 7-membered oxazepine and 8-membered oxazocine derivatives were synthesized by photoreaction of phthalimide derivatives and an alkene. The antimicrobial activities of the synthesized compounds were evaluated, and compounds 18 and 20 exhibited best antibacterial activity against Gram-positive bacteria. The relationships between structure (especially steric structure) and ant...

Dibromobenzoisofuranone 12, synthesized in six steps, was regiospecifically annulated with 5-substituted cyclohexenones 13/36 in the presence of LiOt-Bu to give brominated anthraquinones 14/38 in good yields. Darzens condensation of 30 was shown to give chain-elongated anthraquinone 32. Alkaline hydrolysis of 38 furnished 39 representing desulfoproisocrinin F.

A one-pot asymmetric Michael addition/hydroalkoxylation sequence, catalyzed by a sequential catalytic system consisting of a squaramide and a silver salt, provides a new series of chiral pyrano-annulated pyrazole derivatives in excellent yields (up to 95%) and high enantioselectivities (up to 97% ee).

the kinetics and mechanism of the reaction between benzaldehyde 1, malononitrile 2 and dimedone 3 in a mixture of ethanol and water as solvents in the presence of fructose as a biodegradable catalyst has been studied by the spectroscopic method (uv-vis spectrophotometry method). the influence of various parameters (temperature, solvent and concentration) was studied on the reaction by means of ...

Abstract Based on structures determined by X-ray crystallography, ab initio MP2 calculations type A mesoionic rings give geometries in good agreement with observed values. study of four ring systems, each exocyclic oxygen, nitrogen or carbon groups, shows that the presence and configuration lone pairs significantly influences geometry configurational preference. Using a localised bond model NBO...

The title compound C28H22O2, basically consists of three ring systems, viz. a central benzene ring, with a lateral napthalene group to which it subtends a dihedral angle of 66.56 (4)° and a tetra-hydro-pyran ring exhibiting a half-chair conformation. The mol-ecular structure is stabilized by a weak intra-molecular C-H⋯O inter-action, while the crystal packing features weak C-H⋯π contacts.

The title compound, alternatively called d-fructose-2-amino-isobutyric acid (FruAib), C10H19NO7, (I), crystallizes exclusively in the β-pyran-ose form, with two conformationally non-equivalent mol-ecules [(IA) and (IB)] in the asymmetric unit. In solution, FruAib establishes an equilibrium, with 75.6% of the population consisting of β-pyran-ose, 10.4% β-furan-ose, 10.1% α-furan-ose, 3.0% α-pyra...

An efficient and convenient method for synthesis of 2,6-bis (4-(dialkylamino) styryl)-4H-pyran-4-one starting from 4- (dialkylamino) benzaldehyde with 2,6-dimethyl-4H-pyran-4-onein the presence of MeONa as the base was described. Additionally, preparation of novel compounds with bis-DCM-type skeleton for application in organic light-emitting diodes was developed via reactio...