Synthesis of dibenzopiperidinoaza-14-crown-4 ethers and their one-step conversion into dibenzo-16-crown-3

New dibenzoaza-14-crowns-4 containing a fragment of γ-piperidone, in which 2,6-diaryl substituents are connected with polyethylene oxide bridges, were obtained by the Petrenko-Kritchenko reaction and then transformed by acylation into dibenzo-16-crowns-3.