Synthesis of Macrocyclic Derivatives Containing a Sucrose Unit †
摘要:
An efficient synthesis of 1',2,3,3',4,4'-hexa-O-benzylsucrose (48% from sucrose) is presented. This diol was used for the preparation of crown ether-type analogs of various size macrocyclic rings with incorporated sucrose units.
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 (H-2/Pd/C) without destroying the (very labile) glycosidic bond. The crystal structure of the selected receptor was determined. (c) 2005 Elsevier Ltd. All rights reserved.