Dimethyl 2-[24-acetyl-28-oxo-8,11,14-trioxa-24,27-diazapentacyclo[19.5.1.1 22,26 .0 2,7 .0 15,20 ]octacosa-2,4,6,15(20),16,18-hexaen-27-yl]but-2-enedioate

The title compound, C 31 H 34 N 2 O 9 , is a product of the Michael addition of the cyclic secondary amine subunit of the (bispidino)aza-14-crown-4 ether to dimethyl acetylenedicarboxylate. The molecule comprises a tricyclic system containing the aza-14-crown-3 ether macrocycle and two six-membered piperidinone rings. The aza-14-crown-3-ether ring adopts a bowl conformation with a dihedral angle between the planes of the fused benzene rings of 51.14 (5)°. The central piperidone ring has a boat conformation, whereas the terminal piperidone ring adopts a chair conformation. The dimethyl ethylenedicarboxylate fragment has a cis configuration with a dihedral angle of 56.56 (7)° between the two carboxylate groups. The crystal packing is stabilized by weak C—H...O hydrogen bonds.