The crystal structure and absolute configuration of cedryl chromate

(+)-Cedrol hemihydrate: a natural product derived from drying eastern red cedar (Juniperus virginiana) wood

Cedrol-like compounds are of pharmacological interest due to their diverse range of medicinal effects and are used globally in traditional medicines and cosmetics. Many cedrol tautomers are known from molecular studies but few have been studied in crystalline form by X-ray diffraction. Acicular white crystals collected from the wood of eastern red cedar (Juniperus virginiana) are determined to be (+)-cedrol hemihydrate, namely, (1S,2R,5S,7R,8R)-2,6,6,8-tetramethyltricyclo[5.3.1.01,5]undecan-8-ol hemihydrate, C15H26O·0.5H2O, a novel packing of two unique cedrol molecules (Z' = 2) with a single water molecule [space group P212121; a = 6.1956 (1), b = 14.5363 (1), and c = 30.9294 (4) Å]. The hydrogen bonding forms a one-dimensional spiral chain running along the a axis, following the chirality of the cedrol molecule, through hydrogen-bonding interactions with a right-handed helical configuration in graph-set notation Δ-C33(6) > a > c > b. The crystal packing and symmetry are different from crystalline isocedrol due to the different hydrogen-bonding geometry.

Crystal structure of 1beta-hydroxy-beta-homopipitzolone (9-hydroxy-2,6,9-trimethyltricyclo[6,3,1,0(1,6)]dodeca-5,10,11,12-tetraone)

C15H18O5 is orthorhombic, P2(1)2(1)2(1). The unit-cell dimensions at 293 K are a = 6.526(3), b = 10.247(4), c = 21.008(13) A, V = 1404.8(12) A3, Dx = 1.316 g/cm3, and Z = 4. The R value is 0.044 for 1288 observed reflections. The A, B and C rings adopt chair, twist, and half-chair conformations. The absolute configuration is inferred from the C6 stereochemistry of (+)-cedrol. The crystal structure is stabilized by an O-H...O hydrogen bond and van der Waals forces.