In the title compound, C(17)H(15)N(3)O(4), the atoms of the spiro pyran ring are nearly planar with a maximum deviation of 0.0188 (14) Å. The benzene and pyrrole rings make a dihedral angle of 5.71 (6)°. The indole system and the pyran ring are oriented at a dihedral angle of 82.94 (3)°. The crystal structure is stabilized by inter-molecular classical and non-classical N-H⋯O, N-H⋯N and C-H⋯O hy...

The title compound, C(6)H(12)O(5), is the α-pyran-ose form of the reducing aldose 2-de-oxy-d-arabino-hexose. The six-membered pyran-ose ring adopts a (4)C(1) conformation, with the anomeric hy-droxy group in axial and the other substituents in equatorial positions. In the crystal, each of the four hy-droxy groups acts as an inter-molecular hydrogen-bond donor function, resulting in a three-dime...

The title compound, C(25)H(21)ClO(2), was synthesized via the three-component coupling of 4-chloro-benzaldehyde, 2-naphthol and 5,5-dimethyl-cyclo-hexane-1,3-dione. The pyran ring adopts a boat conformation, while the cyclo-hexenone ring is in an envelope conformation. The 4-chloro-phenyl ring is almost perpendicular to the pyran ring [dihedral angle = 87.39 (1)°]. In the crystal, mol-ecules ar...

In the title compound, C(14)H(11)BrN(2)O(3)S, the 2,3-dihydro-thio-phene ring is almost planar [maximum deviation = 0.006 (1) Å]. The pyran ring is in an envelope conformation [puckering parameters Q = 0.115 (2) Å, θ = 77.5 (10), ϕ = 172.9 (10)°]. The pyran and phenyl rings are approximately perpendicular, making a dihedral angle of -76.4 (2)°. The crystal packing is stabilized by inter-molecul...

In the title compound, [Fe(C5H5)(C14H10NO3)], the cyclo-penta-dienyl rings are in an eclipsed conformation and the pyran ring adopts a half-chair conformation. The mean plane of the pyran ring makes dihedral angles of 79.33 (1) and 80.73 (1)°, respectively, with the substituted and unsubstituted cyclo-penta-dienyl rings. In the crystal, pairs of C-H⋯O hydrogen bonds link the mol-ecules into inv...

New activated macrophage-specific antigen (AcM.1) detected by a monoclonal antibody has been described. The AcM.1 antigen was only detectable on activated macrophages induced by pyran and Corynebacterium parvum but not on resident or thioglycollate medium (TGC), proteose-peptone, and mineral oil-elicited macrophages, and not on blood monocytes and neutrophils. Activated macrophages induced by p...

PYRAN COPOLYMER, A KNOWN IMMUNOSTIMULATOR, WAS FOUND TO BE A POTENT INHIBITOR OF PURIFIED DNA POLYMERASE (DEOXYNUCLEOSIDETRIPHOSPHATE: DNA deoxynucleotidyltransferase; EC 2.7.7.7) isolated from avian myeloblastosis virus. Unlike other inhibitors, pyran showed unique features of inhibition. It interacts with the polymerase at a region other than the template site. The inhibitory effect was overc...

In the title compound, C20H18O7, the dioxolane ring adopts an envelope conformation with the dimethyl-substituted C atom as the flap, and its mean plane makes a dihedral angle of 73.25 (2)° with the pyran ring mean plane. The furan ring makes dihedral angles of 67.43 (12) and 6.20 (11)° with the mean plane of the dioxolane and pyran rings, respectively. The O atom attached to the pyran ring dev...

The reaction of 17,17-dichloro-androst-16(E)-chloromethylene with secondary amine base afforded substitution products exocyclic D-ring ketones, in contrast to the alkaline which cleaved steroidal des-D formyl alkyne. alkyne was employed prepare annulated isoxazolo steroid via 1,3-dipolar nitrile oxide cycloaddition reaction.

Introduction. – The 6-substituted 5,6-dihydro-2H-pyran-2-one A, an a,b-unsaturated d-lactone, is an important structural subunit in many biologically promising natural products. This unit is of interest for a wide variety of biological activities, such as insect-growth inhibitors and insect antifeedent, cytotoxic activities, and antifungal and antitumor properties [1]. The pyran units are widel...