Crystal and molecular structure of 6,7-benzo-3,4 (1,4-dimethoxy-2,3-naphtho)-1,5-dioxosuberane

Abstract

The crystal and molecular structure of the title compound (2) C₂₁H₁₆O₄ has been determined by an X-ray analysis, by direct methods from diffractometer data and refined by full-matrix least squares. The compound (2) crystallizes in the space group P2₁/a, with cell parameters: a = 36.432(5), b = 5.512(3), c = 8.269(5) Å, β= 108.0(3)°, z = 4, D_c = 1.397 g/cm⁻³,R = 7.8 for 1136 observed reflections. The conformation of the tetracyclic ring system shows a folding of two planar parts of the carbon skeleton about an axis passing thorough C8 and C16 of the seven membered ring C.