(1R,2R,7S,8R,9R)-N-(2-Hydroxy-2,6,6,9-tetramethyl-12-oxatricyclo[7.2.1.01,7]dodecan-8-yl)acetamide

Abstract

The title compound, C17H29NO3, was synthesized in two steps from β-himachalene (2,6,6,9-tetramethylbicyclo[5.4.01,7]undeca-1,8-diene), which was isolated from an oil of the Atlas cedar (Cedrus Atlantica). The asymmetric unit contains two independent molecules (A and B): B features an intramolecular O—H...O hydrogen bond whereas A forms an intermolecular O—H...O link to B. Each molecule is built up from a seven-membered ring to which a bridged six-membered ring is fused: the cycloheptane rings have twist-chair conformations, while the bridged cyclohexane rings display near-perfect boat conformations. In the crystal, the molecules are linked by N—H...O and O—H...O hydrogen bonds forming helical chains propagating along the b-axis direction. Some weak C—H...O interactions are also observed.