CRYSTAL AND MOLECULAR-STRUCTURE OF 3-O-ETHYL-8-EPI-9-EPIFURANDIOL, A TRANS-FUSED LACTARANE SESQUITERPENE

3-O-Ethyl-8-epi-9-epi-furandiol (2) has been synthesised from natural 3-O-ethyl-furandiol (Artifact) (1) isolated from extracts of Lactarius vellereus. The structure of 2 was investigated by X-ray diffraction. The compound 2 crystallises in an orthorhombic system, space group P2( 1)2(1)2(1), With cell constants a = 7.308(2), b = 14.629(4), and c = 1 4.702(3) Angstrom. The crystal structure was solved by direct methods and refined by a full-matrix, least-squares procedure to give R = 0.04 5 (R(w) = 0.048, statistical weights). The expected trans-fused config uration of the 7- and 5-membered rings in 2 was fully confirmed. The c onformations of fused rings are discussed.