Crystal structure of (1 RS ,21 SR ,22 RS ,24 SR )-28-oxo-24-propyl-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-hexaene acetic acid monosolvate

The title compound, C 26 H 32 N 2 O 4 ( M )·C 2 H 4 O 2 , (I), is the product of the Petrenko–Kritchenko condensation of N -propylpiperidinone with 1,5-bis(2-formylphenoxy)-3-oxapentane 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 intramolecular N—H...O hydrogen bond. In the crystal, each solvent molecule is linked to molecule M via strong O—H...N hydrogen bonding, forming hydrogen-bonded pairs of molecules, which further interact through weak C—H...O hydrogen bonds, forming layers parallel to the ac plane.