In the title compound, C29H23N3O4, the 2-methylpyrrolidine ring adopts a twist conformation on the N-C bond involving the spiro C atom, while the hydropyran ring adopts an envelope conformation with the methine C atom bonded to the O atom as the flap. The mean plane of the indoline-2-one ring system is almost perpendicular to the mean plane of the pyrrolidine ring, making a dihedral angle of 89...