X-ray investigations of bicyclic α-­methyl­ene-δ-valerolactones. V. (4aS,7R,8aR)-7-Isopropenyl-4a-methyl-3-methyl­eneperhydro­chromen-2-one

The title compound, C₁₄H₂₀O₂, adopts a conformation in which the δ-valerolactone and cyclo­hexane rings are almost coplanar with one another. The γ-methyl substituent occupies an axial position with respect to the cyclo­hexane ring. The δ-valerolactone moiety adopts an envelope arrangement, while the cyclo­hexane ring exists in a chair conformation.