Experimental Crystal data

R factor = 0.078; wR factor = 0.228; data-to-parameter ratio = 22.8. In the title compound, C29H34N2O2, the central piperidine ring adopts a half-chair conformation, whereas the terminal one adopts a chair conformation. The mean plane of the central piperidine ring [maximum deviation = 0.384 (2) Å] makes dihedral angles of 64.82 (13) and 17.55 (13) with the benzene rings. In the crystal, molecules are linked into a tape along the b axis via C—H O interactions, generating R22(20) and R21(6) graph-set motifs. C—H interactions are observed between the tapes. Related literature For biological activities of ,-unsaturated ketones, see: Tanaka et al. (2003); Nakayachi et al. (2004); Lee et al. (2004); Hertzberg et al. (1989). For ring conformations, see: Cremer & Pople (1975). For related structures, see: Aridoss et al. (2010); Kia et al. (2011). For graph-set motifs, see: Bernstein et al. (1995). For the preparation of 1-acryloyl-3,5-dibenzyl-idenepiperidin-4-one, see: Dimmock et al. (2001). For the stability of the temperature controller used for data collection