(+)-(1S,5R,10S)-11,11-Dimeth­yl-4-oxa­tricyclo­[8.4.0.0(1,5)]tetra­deca­ne-3,12-dione

The title compound, C(15)H(22)O(3), 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.