Absolute configuration of (1R,3S,8R,11R)-3,7,7,10-tetra-methyl-tri-cyclo-[6.4.0.0(1,3)]dodec-9-en-11-ol.

The absolute configuration of the title compound, C16H26O, was determined as (1R,3S,8R,11R) based mainly on the synthetic pathway but is also implied by the X-ray analysis. The mol-ecule contains fused six- and seven-membered rings. Part of the seven-membered ring was refined as disordered over two sets of sites with the occupancy ratio fixed at 0.86:0.14. The disorder corresponds to a major chair conformation and a minor boat conforation. In the crysyal, O-H⋯O hydrogen bonds connect the mol-ecules into chains parallel to the a axis.