Crystal structure and Hirshfeld surface analysis of dimethyl (1 R*,3a S*,3a1 R*,6a S*,9 R*,9a S*)-3a1,5,6,9a-tetra-hydro-1 H,4 H,9 H-1,3a:6a,9-di-epoxy-phenalene-2,3-di-carboxyl-ate

Acta Crystallogr E Crystallogr Commun. 2019 Mar 20;75(Pt 4):460-464. doi: 10.1107/S2056989019003499. eCollection 2019 Apr 1.

Abstract

The title di-epoxy-phenalene derivative, C17H18O6, comprises a fused cyclic system containing four five-membered rings (two di-hydro-furan and two tetra-hydro-furan) and one six-membered ring (cyclo-hexa-ne). The five-membered di-hydro-furan and tetra-hydro-furan rings adopt envelope conformations, and the six-membered cyclo-hexane ring adopts a distorted chair conformation. Two methyl carboxyl-ate groups occupy adjacent positions (2- and 3-) on a tetra-hydro-furan ring. In the crystal, two pairs of C-H⋯O hydrogen bonds link the mol-ecules to form inversion dimers, enclosing two R 2 2(6) ring motifs, that stack along the a-axis direction and are arranged in layers parallel to the bc plane.

Keywords: C—H⋯O hydrogen bonds; Hirshfeld surface analysis; crystal structure; di­epoxy­phenalene; fused hexa­cyclic system.

Grants and funding

This work was funded by Russian Science Foundation grant 18–13-00456.