In the title compound, C14H20O5, an inter-mediate in the synthesis of oligosaccharides, the glycosidic [H-C-O-C(H3)] torsion angle ϕH is 52.3° and the exo-cyclic [H-C-O-C(H2)] torsion angle θH is -11.7°. The hexa-pyran-ose ring has a chair conformation. In the crystal, mol-ecules are linked by O-H⋯O hydrogen bonds, forming chains propagating along [010]. Enclosed within the chains are R 3 (3)(1...

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...

In the title compound, C(22)H(21)N, the pyridine ring adopts a distorted boat conformation, while the adjacent pyran ring adopts a chair conformation; the heterocyclic rings make a dihedral angle of 40.1 (2)° with each other.

The title compound, C(10)H(7)FO(4), is an inter-mediate in the synthesis of the drug Fidarestat, (2S,4S)-2-aminoformyl-6-fluoro-spiro[chroman-4,4'-imidazolidine]-2',5'-dione. The di-hydro-pyran-one ring adopts an envelope conformation with the asymmetric C atom in the flap position. In the crystal, the mol-ecules are linked into zigzag chains along [100] by O-H⋯O hydrogen bonds and C-H⋯π inter-...

In the title compound, C(24)H(22)BrNO(3), the dihydro-pyran ring adopts a half-chair conformation, whereas the pyrrolidine ring is in an envelope conformation. The bromo-phenyl group is oriented at an angle of 66.44 (4)° with respect to the naphthalene ring system. In the crystal structure, mol-ecules are linked into centrosymmetric dimers by C-H⋯π inter-actions and the dimers are connected via...

In the title compound, C28H23N3O2, the pyrazole ring makes a dihedral angle of 16.90 (6)° with the phenyl ring to which it is attached. Both di-hydro-pyran rings exhibit half-chair conformations. Intramolecular C-H⋯O interactions generate S(6) and S(8) ring motifs. In the crystal, weak C-H⋯O and C-H⋯π interactions occur.

An overview of the synthesis of the fungal metabolites (+)-dermolactone, (-)- semixanthomegnin, (+)- and (-)-mellein, (-)-ochratoxin alpha, (-)-(1R,3S)-thysanone, the enantiopure ventiloquinones L, E and G, and 8-desmethyleleutherin from a common chiral intermediate, is presented. Further methodology leading potentially toward extended quinones such as (3S,3'S)-xylindein is also outlined.

In the title compound, C(20)H(29)NO(8)S, the two five-membered rings adopt envelope conformations (with an O atom at the flap in each case), while the six-membered pyran ring displays a twist-boat conformation. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds into a supra-molecular chain running along the a axis.

In the title compound, C19H14FN3O3, the central pyran ring adopts a boat conformation with the O atom and the quaternary C atom diagonally opposite displaced by 0.068 (1) and 0.075 (1) Å, respectively, above the mean plane defined by the other four ring atoms. The co-planar atoms of the pyran ring and the fluoro-phenyl ring are nearly perpendicular, as evidenced by the dihedral angle of 87.11 (...

In the mol-ecule of the title compound, C(21)H(22)N(2)O(5), the indole system and the spiro-pyran ring are almost planar [maximum deviations of 0.0447 (17) and 0.0781 (17) Å, respectively]; the dihedral angle between them is 84.6 (3)°. The remaining six-membered ring adopts a twisted conformation. Intra-molecular N-H⋯O hydrogen bonds occur. In the crystal structure, intera-molecular N-H⋯O and C...