3-Arylhydrazono-2,4-dioxo-4-phenylbutanoateshave been prepared by the coupling of benzoylpyruvate with aryldiazonium chlorides.Reactions ofthe 3-arylhydrazono-2,4-dioxo-4-phenylbutanoateswith 1-aminoguanidine, semicarbazide, and thiosemicarbazidegave5-substituted 2-imino-6-azauracil (3a),6-azauracil (3b), and 2-thio-6-azauracil (3c), respectively. The analytical data of these compounds - IR, 1H...

The title complex, [Mg(C7H7N4O2)2(H2O)4], lies across an inversion centre and the Mg(II) atom is coordinated in a slightly distorted octa-hedral environment by four aqua ligands in the equatorial sites and two 1,3-dimethyl-2,6-dioxo-3,7-di-hydro-1H-purin-9-ide ligands, through imidazole ring N atoms, in the axial sites. An intra-molecular O-H⋯O hydrogen bond forms an S(7) graph-set motif. In th...

The title compound, C(31)H(38)O(10) [systematic name: (αR,4R,4aR,6aS,7R,8S,10R,11S)-methyl α,10-di-acet-oxy-4-(3-furyl)-4a,7,9,9-tetra-methyl-2,13-dioxo-1,4,4a,5,6,6a,7,8,9,10,11,12-dodeca-hydro-7,11-methano-2H-cyclo-octa-[f][2]benzo-pyran-8-acetate], was isolated from the seeds of Swietenia macrophylla. The mol-ecule contains four six-membered rings connected together in the shape of a bowl; o...

The biocatalyzed conversion of hyocholic acid (3α,6α,7α-trihydroxy-5β-cholan-24-oic acid) into ω-muricholic (3α,6α,7β-trihydroxy-5β-cholan-24-oic has been obtained exploiting a small library 7α- and 7β-HSDHs (hydroxysteroid dehydrogenases). process optimized performed avoiding the isolation 7-oxo intermediate using appropriate coupled enzymes for in situ cofactor regeneration. Moreover, reducti...

Starting from enantiomeric pure 1-[(3S,5R)- and 1-[(3R,5S)-3-(hydroxymethyl)-2-methylisoxazolidin-5-yl]-5-methylpyrimidine-2,4(1H,3H)-diones (-)7a and (+)7b, obtained by lipase-catalyzed resolution, pure diethyl{[(3S,5R)-2-methyl-5-(5-methyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)isoxazolidin-3-yl]methyl}phosphonate (-)12a and diethyl{[(3R,5S)-2-methyl-5-(5-methyl-2,4-dioxo-3,4-dihydropyrimidi...

The reaction of 5,5-dimethylcyclohexane-1,3-dione with various heteroarylaldehydes afforded the corresponding heteroaryl substituted xanthene derivatives 1(a-f). The reaction proceeds via the initial Knoevenagel, subsequent Michael, and final heterocyclization reactions using 1,4-diazabicyclo[2.2.2]octane (DABCO) as a catalyst in aqueous media. The synthesized heteroaryl substituted xanthenes 1...

We present a design strategy for fluorescence probes with a high off/on activation ratio in the red wavelength region, based on a novel fluorescein analogue in which the O atom at the 10 position of the xanthene chromophore is replaced with a Si atom. To demonstrate the usefulness of this strategy, we designed and synthesized a red-fluorescent probe for β-galactosidase, and showed that it works...

In the title compound, C(21)H(21)NO(6), each of the cyclo-hexenone rings adopts a half-chair conformation. Each of the pairs of hy-droxy and carbonyl O atoms are oriented to allow for the formation of intra-molecular O-H⋯O hydrogen bonds, which are typical of xanthene derivatives.