(3R,4aS,5R)‐3‐Hydro­xy‐5‐isopropenyl‐3,8‐di­methyl‐4,4a,5,6‐tetra­hydro‐2(3H)‐naphthalenone

In the crystal structure of C₁₅H₂₀O₂, mol­ecules are associated by intermolecular hydrogen bonds between the hydroxy function and a keto group O?O 2.770 (2) Å], forming chains along the 100] direction in the crystal. Both six‐membered rings in the decalin unit adopt envelope conformations; one section of the mol­ecule, encompassing the extended conjugation of a C=C double bond with an enone functionality C=C—C=O = 175.6 (2)° and C=C—C=C = 176.6 (2)°], is flat, whilst the rest of the mol­ecule is folded relative to the constrained part. The stereochemistry was determined from the R‐(–)‐carvone starting material.