In the title compound, C(35)H(36)N(2)O(5)·0.5C(4)H(10)O, the asymmetric unit contains one bicyclo-[3.3.1]nonane mol-ecule and a half-occupancy diethyl ether solvent with the O atom lying on a crystallographic inversion center. Two intra-molecular N-H⋯O hydrogen bonds generate S(6) ring motifs. The bicyclo-[3.3.1]nonane ring system adopts a chair-boat conformation. In the crystal structure, the mol-ecules are linked by weak inter-molecular C-H⋯N hydro-gen bonds into chains along the b axis; additional stabilization is provide by C-H⋯π inter-actions.