In the title compound, C(26)H(12)FNO(6), the central pyran ring and both benzopyran systems are nonplanar, having total puckering amplitudes of 0.139 (2), 0.050 (1) and 0.112 (2) Å, respectively. The central pyran ring adopts a boat conformation. The crystal structure is stabilized by C-H⋯O, N-H⋯O, N-H⋯F and C-H⋯π inter-actions.

In the title compound, C20H14N2O, the phenyl ring is almost normal to the naphthalene ring system with a dihedral angle of 86.72 (9)°. The 4H-pyran ring fused with the naphthalene ring system has a boat conformation. In the crystal, mol-ecules are linked into a helical supra-molecular chain along the b axis via N-H⋯N hydrogen bonds. The chains are consolidated into a three-dimensional architect...

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)°].

In the title compound, C(25)H(27)NO(5), each of the cyclo-hexenone rings adopts a half-chair conformation, whereas the six-membered pyran ring adopts a flattened boat conformation, with the O and methine C atoms deviating from the plane of the other four atoms. In the crystal, weak C-H⋯O hydrogen bonds link mol-ecules into chains parallel to the c axis.

The structure of the natural dipyranocoumarin dipetalolactone has been confirmed by an unambiguous synthetic route from resorcinol. This sequence was initiated by a pyran ring formation step which introduced the 3-chloro-3-methylbut-1-yne moiety. Then, the expected product undergoes a Fremy's salt-meditated oxidative addition followed by ring closure to yield dipetalolactone. Dipetalolactone wa...

Since their isolation almost 20 years ago, the callipeltosides have been of long standing interest to the synthetic community owing to their unique structural features and inherent biological activity. Herein we present our full research effort that has led to the synthesis of these molecules. Key aspects of our final strategy include 1) synthesis of the C1-C9 pyran core (5) using an AuCl3 -cat...

Ruthenium complexes are remarkable catalysts for the C–H activation approaches and organic transformations. Combining a Ru-catalyst with oxidants other additives in one-pot process is considered sustainable approach due to reduction reaction steps minimal usage of solvents during synthesis, work-up, isolation chemicals, purification products. This review highlights ruthenium-catalyzed transform...

In the title compound, C(32)H(37)NO(8), the central pyran ring adopts a twist-boat conformation and the 1,3-dioxoane rings adopt envelope conformations. The acenaphthyl-enone unit and two C atoms of a pyrrolidine ring are disordered over two sets of sites [occupancy ratio 0.669 (7):0.331 (7)]. The major fraction of the disordered pyrrolidine ring exhibits an envelope conformation while the mino...

In the mol-ecule of the title compound, C(20)H(11)ClN(2)O(3), the pyran ring adopts a flattened-boat conformation. In the crystal structure, inter-molecular N-H⋯N and N-H⋯O hydrogen bonds generate edge-fused R(2) (2)(12) and R(2) (2)(14) ring motifs; the hydrogen-bonded motifs are linked to each other, forming a three-dimensional network. A π-π contact [centroid-to-centroid distance = 3.879 (3)...