Synthesis, Crystal Structure and Theoretical Characterization of (3R, 4R, 6S)-3,6-Dihydroxy-1-Menthene Isolated from Echinophora Tenuifolia

Abstract

In the title compound, C10H18O2, the cyclohexene ring adopts a half-chair conformation. In the crystal strcuture, weak inter(sic)molecular O-H center dot center dot center dot O hydrogen bonds connect the adjacent molecules, forming edge-fused R23(8) ring motifs, into the hollow columns parallel to the b-axis direction. The crystal packing is governed only by van der Waals inter(sic)actions. There is no further C-H center dot center dot center dot pi and pi-pi interactions. The H atom in one of two hydroxyl groups was found to be disordered over two sites. The occupancy factors of the two sites were refined to 0.52 (2) and 0.48 (2). Semi-empirical PM3 quantum chemical calculations are in satisfactory agreement with the results of the X-ray structure analysis.