4a-hydroxy-9-(2-methoxyphenyl)-4,4a,5,6,7,8,9,9a-octahydro-3hxanthene-1, 8(2H)-dione

Abstract

In the title compound, C20H22O5, an S(6) ring motif is formed by an intramolecular C-H ⋯ O hydrogen bond, which contributes to the stabilization of the molecule. In the xanthene system, the cyclohexane ring adopts a chair conformation, the cyclohexene ring adopts a half-boat conformation and the tetrahydropyran ring adopts a halfchair conformation. The mean plane of the four essentially planar atoms of the tetrahydropyran ring [r.m.s deviation = 0.092 (1) Å] forms a dihedral angle of 64.13 (6)° with the mean plane of the methoxyphenyl group. In the crystal, intermolecular O-H ⋯ O and weak C-H ⋯ O hydrogen bonds link molecules into chains along the a axis, which are further stabilized by C-H ⋯π interactions.