Acta Crystallographica Section E (Jan 2011)
7-Deacetylgedunin
Abstract
The title compound [systematic name: (1S,3aS,4aR,4bS,5R,6aR,10aR,10bR,12aS)-1-(furan-3-yl)-5-hydroxy-4b,7,7,10a,12a-pentamethyl-4b,5,6,6a,7,10a,10b,11,12,12a-decahydronaphtho[2,1-f]oxireno[2,3-d]isochromene-3,8(1H,3aH)-dione], C26H32O6, which is a limonoid-type triterpene isolated from the seeds of X. moluccensis, crystallizes with three independent molecules with very similar geometries in the asymmetric unit. In each molecule, the four fused six-membered rings of the genudin core adopt distorted half-chair, chair, twist-boat and twisted half-chair conformations. In the crystal, intermolecular O—H...O hydrogen bonds link the molecules into helical chains propagated in [100]. Weak non-classical C—H...O contacts further consolidate the crystal packing.