Crystal Structure and Absolute Configuration of Pendulone

Abstract

The complete structure of the title compound, C17H16O6, isolated from the roots of Oxytropis falcata Bunge, was confirmed unambiguously by a single-crystal X-ray analysis. The absolute configuration was established by circular dichroism (CD). The bond distances and angles are within the expected ranges. The quinone ring is linked to the chroman ring by C(3) at an equatorial position. The crystal structure is also stabilized by intermolecular hydrogen bonds.