Crystal structure of (1RS,21SR,22RS,24SR)-28-oxo-24-propyl-8,11,14-trioxa-24,27-di-aza-penta-cyclo[19.5.1.1(22,26).0(2,7).0(15,20)]octa-cosa-2,4,6,15(20),16,18-hexa-ene acetic acid monosolvate.

The title compound, C26H32N2O4(M)·C2H4O2, (I), is the product of the Petrenko-Kritchenko condensation of N-propyl-piperidinone with 1,5-bis-(2-formyl-phen-oxy)-3-oxa-pentane and ammonium acetate. In M, the aza-14-crown-3-ether ring adopts a bowl conformation, with the configuration of the C-O-C-C -O-C-C-O-C polyether chain being t-g ((-))-t-t-g ((+))-t (t = trans, 180°; g = gauche, ±60°). The dihedral angle between the planes of the benzene rings fused to the aza-14-crown-4-ether moiety is 62.75 (5)°. The central piperidinone ring has a boat conformation, whereas the terminal piperidinone ring adopts a chair conformation. The boat conformation of the central piperidinone ring is supported by the bifurcated intra-molecular N-H⋯O hydrogen bond. In the crystal, each solvent mol-ecule is linked to mol-ecule M via strong O-H⋯N hydrogen bonding, forming hydrogen-bonded pairs of mol-ecules, which further inter-act through weak C-H⋯O hydrogen bonds, forming layers parallel to the ac plane.