Enantiomerically pure (4aS,7S,8aS)-7-isopropenyl-4a-methyl-3-methyleneperhydro-chromen-2-one, C14H20O2, crystallized in an orthorhombic system: cell constants a = 6.565(1), b = 10.880(2), c = 17.716(4)Å; V = 1265.5(4)Å3; space group P212121Z = 4. The title compound adopts a semi-folded conformation in which the δ-valerolactone and cyclohexane rings are almost perpendicular to one another. Both oxygen atoms are not involved in nonbonding intramolecular contacts with the neighboring atoms.
