T. J. Van Bergen

X-Ray crystal structure of a 1,4-dihydropyridine-crown ether–sodium perchlorate complex crystallized with a molecule of acetone

The crown ether–1,4-dihydropyridine (1) complexes with NaClO4 and forms crystals containing a molecule of acetone co-ordinated to Na+; an X-ray structural determination reveals the dihydropyridine ring to be in a pronounced boat conformation and tilted relative to the polyethyleneglycol chain.

Synthesis of crown ethers containing the 3,5-di(alkoxycarbonyl)pyridine ring system by means of the Hantzsch condensation

The products obtained from reaction of ethyl acetoacetate with several (poly)ethyleneglycols undergo the Hantzsch condensation with ammonium carbonate and formaldehyde giving new crown ethers; transformations and properties of these new compounds are described.