In the title compound, C(22)H(29)N(3)O(5)S, the pyrrolidine ring is cis-fused to the dihydro-pyran ring. The pyrrolidine and dihydro-pyran rings adopt twist and half-chair conformations, respectively. The mol-ecule is in a folded conformation; the sulfonyl-bound benzene ring lies over the pyrimidine-dione ring, with a weak π-π inter-action [centroid-centroid distance = 3.6147 (4) Å]. A weak int...

In the title compound, C(19)H(16)O(4), there are two 4-hy-droxy-benzyl substituents on the oxan-4-one (tetra-hydro-pyran-4-one) ring, which exhibits an envelope conformation. The dihedral angles between pyran-one ring and the two benzene rings are 26.69 (9) and 36.01 (9)° while the benzene rings make a dihedral angle of 20.88 (10)°. In the crystal, mol-ecules are linked by inter-molecular O-H⋯O...

In the title mol-ecule, C19H17F3N2O2, the fused cyclo-hexene and pyran rings adopt sofa and flattened boat conformations, respectively. The four essentially planar atoms of the pyran ring [maximum deviation = 0.008 (2) Å] form a dihedral angle of 88.13 (9)° with the benzene ring. The F atoms of the trifluoro-methyl group were refined as disordered over three sets of sites in a 0.507 (7):0.330 (...

Herein, the synthesis and crystal structure of 7-hy-droxy-3-(2-meth-oxy-phen-yl)-2-tri-fluoro-meth-yl-4H-chromen-4-one, C17H11F3O4, are reported. This isoflavone is used as a starting material in the preparation an array of potent and competitive FPR antagonists. The pyran ring significantly deviates from planarity and the dihedral angle between the benzo-pyran mean plane and that of the exocyc...

ABSTRACT. Benzoylacetone (1) underwent a series of multi-component reactions with aromatic aldehydes and malononitrile or ethyl cyanoacetate to produce the pyran derivatives 4a-f. The latter compounds reacted yield condensation products 5a-m. On other hand, reaction 4a-f either diazonium salts 6a-c yielded arylhydrazone 7a-i. adehydes cyclohexan-1,3-dione produced 9a-c. Compound 1 Gewald’s elem...

a simple, efficient, and high yielding one-pot protocol has been developed for the synthesis of 4h-benzo[b]pyrans scaffolds installing a three-component tandem knoevenagel-cyclocondensation reaction of an aldehyde, malononitrile and dimedone using guanidinium chloride as polyfunctional organocatalyst under solvent-free conditions in high to excellent yields. various aromatic aldehydes were util...

In the title compound, C10H4Cl2O3, a dichlorinated 3-formyl-chromone derivative, the fused-ring system is slightly puckered [dihedral angle between the benzene and pyran rings = 3.66 (10)°]. The dihedral angle between the pyran ring and the formyl plane is 8.64 (7)°. In the crystal, mol-ecules are linked through π-π stacking inter-actions [centroid-centroid distance between the benzene and pyra...

Irradiation of pyran-2-ones bearing pendent furans in aqueous MeOH followed by heating furnished fused bicyclic products containing a cyclooctatriene ring.

In the title compound, C(20)H(20)FNO(3), the pyrrolidine and benzopyran rings adopt half chair and twisted half chair conformations, respectively. The carboxyl-ate group is almost perpendicular to the pyran ring [89.4 (1)°].

Through the studies on structure-activity relationships o f 5-acyl-3-(l-aminoalkylidene)4-hydroxy-2 H-pyran-2,6(3 H)-dione derivatives in photosystem II (PS II) inhibition, overall lipophilicity o f the molecule was found to be a major determinant for the activity. In the sub­ stituted N-benzyl derivatives, not only the lipophilicity but also the electronic and steric char­ acters o f the subst...