In the title compound, C31H33N3O2, the spiropyrrolidine ring has a twisted conformation on the Cspiro—N bond, whereas the tetrahydropyran ring adopts a sofa confirmation. The spiro joined fragments are almost orthogonal, with a dihedral angle of 89.1 (2)° between the mean planes of the pyrrolidine and tetrahydropyran rings. In the diethylamine group, the ethanamine portion is disordered over the two positions, with a refined occupancy ratio of 0.73 (1):0.27 (1). In the crystal, molecules are linked by pairs of C—H...O hydrogen bonds, forming inversion dimers with an R22(10) ring motif. The dimers are linked by further C—H...O hydrogen bonds, forming slabs parallel to (100).
