Macrocyclic receptors containing sucrose skeleton

Crown ether analogues with incorporated sucrose unit were prepared by reaction of 1′,2,3,3′,4,4′-hexa-O-benzylsucrose with polyethylene ditosylates in up to 52% yield. Stability constants of their complexes with Li+, Na+, K+, NH4+ were determined by the NMR titration method. The macrocycles were also tested as catalysts in the enantioselective Michael reaction, but with little success (ee up to only 22%). The macrocycle containing nitrogen in the ring was also prepared in good yield. All prepared macrocycles were easily converted into the free sucrose crowns (H2/Pd/C) without destroying the (very labile) glycosidic bond. The crystal structure of the selected receptor was determined.