A second polymorph of (+)-pinoresinol–dioxane (1/1)

Abstract

The crystal structure of the title compound, C20H22O6·C4H8O2, has been determined. The crystals are stabilized by O-H...O hydrogen bonding between the pinoresinol and dioxane molecules. C-H...O hydrogen bonds are absent, but are present in a previously reported polymorph of the solvate. The formation of two polymorphs may be related to different hydrogen-bonding possibilities. The five-membered rings in the central dioxabicyclooctane ring system of the pinoresinol molecules in the title compound are twisted on the benzylic C and the O atom.