Antimalarial bioassay-guided fractionation of an EtOH extract of the root wood of Cryptocarya rigidifolia (Lauraceae) led to the isolation of the five new 5,6-dihydro-α-pyrones cryptorigidifoliols A-E (1-5) and the six bicyclic tetrahydro-α-pyrone derivatives cryptorigidifoliols F-K (6-11). The structure elucidations of all compounds were made on the basis of the interpretation of spectroscopic...

an efficient synthesis of some novel coumarin derivatives via 1, 4- michael addition of indole to coumarin chalcones catalyzed by cellulose sulphonic acid (csa) under solvent free conditions is described. the corresponding michael addition products were obtained in good to excellent yield. the synthesized compounds were screened for their antibacterial activity against e. coli, s. aureus and an...

Enantioselective C-H addition is one of the most straightforward and efficient approaches towards synthesis optically active molecules from readily available arenes. The significant feature these reactions that nucleophilic aryl metal species generated catalytically in situ via C–H bond activation. These typically proceed without requirement either strongly basic or acidic conditions, thus with...

the anticoagulant racemic warfarin is synthesized by the michael addition of 4-hydroxycoumarin with benzalacetone in the present of equimolar amounts of imidazolium based ionic liquids [bmim] bf4 and [bmim] br and other reaction solvents such as h2o, pyridine and ammonia in five different tests. also synthesis of a derivative of warfarin (2-methyl-4-phenyl pyrano [3, 2-c] chromen-5(4h)-one) und...

An intramolecular palladium catalysed carbometalation followed by anion capture achieves construction of a model comprised of the A ring of Vitamin D oxygen analogues.

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Protonation of the reactive intermediates generated in the raction between dalkyl acetylenedicarboxylates and triphenylphosphine by isonitrosoacetophenone leads to vinyltriphenylphosphonium salts, which undergo intramolecular Wittig reaction to produce dalkyl 4-phenyl-N-hydroxypyrrole-2,3-dicarboxylates in moderate yields.

Examples of inter- and intramolecular direct co-functioning of lectins and enzymes are summarized. The data indicate importance of lectin-enzyme relationships in molecular and clinical microbiology and medical biotechnology. Lectin-enzyme relationships have extended prospects in medicine and biotechnology.

The N-(2-benzoyl-phenyl) oxalyl derivatives are important models for studying of three-centered intramolecular hydrogen bonding in organic molecules. The quantum theoretical calculations for two crystal structures of N-(2-benzoyl-phenyl) oxalyl (compounds I and II) were performed by Density Functional Theory (B3LYP method and 6-311+G* basis set). From the optimized structures, geometric paramet...