[6a,16b]-cis-7,7-Dimethyl-6,6a,7,16b-tetrahydrochromeno[4′,3′:3,4]pyrano[3,2-c]-α-naphthocoumarin

Abstract

In the title compound, C25H20O4, the di­hydro­pyran rings adopt distorted sofa conformations. The mol­ecule comprises two planar regions which form a dihedral angle of 62.56 (3)°. C—H⋯π interactions link the mol­ecules to form centrosymmetric dimeric pairs. The dimers are interlinked along the [101] direction by C—H⋯O hydrogen bonds.

6a,14a-cis-6,6a,7,14a-Tetrahydrochromeno[4′,3′:3,4]pyrano[3,2-c]coumarin

“…There are two crystallographically independent molecules in the asymmetric unit. In both molecules, the O1ÐC2 and O1ÐC6 bonds are nearly equal in length, but slightly shorter than previously reported values (Krishna et al, 2003). The C2 O2, C2ÐC3, C3 C4 and C5ÐC6 bond lengths and the endocyclic angles of the pyrone ring (B) agree well with those reported in related structures (Ruggiero et al, 1989;Chinnakali et al, 1992).…”

1,2,3,4,4a,12a-Hexahydro-2,5,5-trimethyl-1H-[2]benzopyrano[3,2-c]coumarin

“…1) contains a fused four-ring system A/B/C/D. The geometry of the coumarin ring system (Table 1) is comparable to that observed in other coumarin derivatives (Chinnakali et al, 1998(Chinnakali et al, , 1999Krishna et al, 2003). The bond lengths in the dihydropyran ring (C) and cyclohexane ring (D) have normal values (Allen et al, 1987).…”