Synthesis and molecular structure of bis(areno)piperidinoaza-14(17)-crowns-4(5)

The condensation of dialkyl ketones with α,ω-bis(2-formylphenoxy)- or α,ω-bis(1-formylnaphthalen-2-yloxy)-3-oxapentane and-3,6-dioxaoctane in the presence of ammonium acetate according to Petrenko-Kritchenko gave 14–41% of new bis(areno) aza crowns, bis(areno)piperidinoaza-14-crown-4 and bis(benzo)-piperidinoaza-17-crown-5, having functional substituents in the piperidine fragment. The yield of the aza crown ether appreciably decreases upon extension of the polyether chain in the aldehyde component. The molecular structure of two of the obtained macrocyclic compounds and the relative configuration of asymmetric carbon atoms in the piperidine ring were determined by X-ray analysis, and the size of their internal cavities was estimated.