Crystal and molecular structure of schkuhriolid monohydrate, a cis, trans-germacra-1 (10),4-dien-cis-8,12-olide

Authors:

• Urszula Rychlewska

Abstract

The crystal structure of the title compound (I) has been determined from three-dimensional X-ray diffractometer data by direct methods. Crystals are orthorhombic, space group P2₁2₁2₁, with Z=4 in a cell of dimensions, a=6.968(1), b=9.603(1), c=22.478(3) A°. Schkuhriolid is a representative of the germacra-cis-1(10), trans-4-diene class of sesquiterpene, sub-group melampolide. The ten-membered ring conformation in schkuhriolid is similar to that found in crystal structures of other malampolides though the mode of the attachment of the γ-lactone ring is different. Schkuhriolid, with a lactone ring closed at C(8) and cis-annelated to the homocyclic ring is the first such melampolide studied by X-ray diffraction.