(+)-(1S,5R,10S)-11,11-Dimethyl-4-oxatricyclo[8.4.0.01,5]tetradecane-3,12-dione

The title compound, C15H22O3, was prepared via amino-acid-promoted Robinson annulation followed by tandem Pd/C-mediated hydrogenation and oxidative cyclization. This product was instrumental in determining the feasibility of a stereocontrolled hydrogenation in which the directing hydroxyl group is adjacent to the 6–7-ring network and its olefinic component. The asymmetric unit consists of a single molecule with normal geometric parameters. The absolute configuration was assigned based on the known enantiomeric prescursor. Intermolecular C—H...O interactions link each molecule with four neighboring molecules.