SYNTHESIS OF TETRAMERIC ARABINOGALACTANS BASED ON 1,2-ANHYDROSUGARS

The spacer-containing tetrameric arabinogalactans 1-3, suitable for CC RC-M7 epitope characterization, are readily accessible by ZnCl2-assist ed stepwise elongation of 11-methoxycarbonylundecanol 9 with the 1,2-a nhydrogalactose building unit 6. NIS/cat. TfOH-mediated glycosylation of the newly formed 2-OH, 2'-OH, or 2 ''-OH function in the beta(1-->6 )-galactoside backbone with the 1-thioarabinofuranoside donor 8, follo wed by deprotection, provided the target tetramers in high overall yie ld.