Influence of Linker Length on Conformational Preferences of Glycosylated Sugar Amino Acid Foldamers.

Glycosylation of foldamers derived from furanoid sugar amino acids with mannose and a propyltriazole linker results in an unprecedented 16/10 mixed-turn structure in the glycopeptides in water, with a preference for the higher-order structure irrespective of the stereochemistry of the starting foldamer. This is in stark contrast to the structures displayed by the same oligomers in water when mannosylated with a two-carbon-shorter methyltriazole linker: 16-membered turn structure in the cis-foldamer and 10-membered in its trans congener. This demonstrates the defining influence of the linker length on the structural preference of these novel glycopeptide mimics.