In order to study structure–activity relationships, a series of mono-, di-and trioxygenated xanthones has been synthesized and the structures of methyl 2-(3, 4-dimethoxyphenoxy) benzoate, C16H16O5, 2-(3, 4-dimethoxyphenoxy) benzoic acid, C15H14O5, 1, 2-dimethoxy- 9H-xanthen-9-one, C15H12O4, and 1, 2, 8-trimethoxy-9H-xanthen-9-one, C16H14O5, have been determined. The first two compounds both assume skew conformations, the dihedral ...