Two high-yielding strategies for the synthesis of 4H-anthra[1,2-b]pyran antibiotics have been developed giving access to novel antitumor agent (ED(50) 1.5 microm) and to (S)-espicufolin (3). A key step for the assembly of the tetracyclic 4H-anthra[1,2-b]pyran-4,7,12-trione skeleton is the nucleophilic addition of an aryl lithium species onto an aldehyde which allows the introduction of either a...

Quinazolinones is an important chemical synthesis with different physiological significance and pharmacological utility. Reaction of anthranilic acid with benzoyl chloride in pyridine yielded 2-phenyl4H-benzo[d][1,3]oxazin-4-one, which on condensation reaction with the tryptophan in glacial acetic acid afforded 3-(1H-indol-3-yl)-2-(4-oxo-2-phenylquinazolin-3(4H)-yl) propanoic acid (2). Treatmen...

Abstract Chelidonic acid (4-oxo-4H-pyran-2,6-dicarboxylic acid) is present in plants of Papaveraceae family, especially Chelidonium majus . Due to its anticancer, antibacterial, hepatoprotective, and antioxidant properties, it has been used medical treatments. In this work, the X-ray structure methanol solvate chelidonic was determined. Layers are held by hydrogen bonds via COOH C = O fragments...

Two new phenols, 2(S)-2',7-dihydroxy-5,8-dimethoxyflavanone and (S)-2-(4-hydroxyphenyl)-6-methyl-2,3-dihydro-4H-pyran-4-one, were isolated from the ethanol extract of Scutellaria barbata. Their structures were elucidated on the basis of spectroscopic analysis.