The Study of the Reaction of Terminated Oligomerization in the Synthesis of Oligo-(β1-6)-Glucosamines

M. L. Gening^a, Yu. E. Tsvetkov^a, G. B. Pier^b, and N. E. Nifantiev^a,#

^# Phone/fax: +7 (495) 135-8784: e-mail: nen@ioc.ac.ru
^a Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninskii pr. 47, Moscow, 119991 Russia
^b Harvard Medical School, Harvard University, and Channing Laboratory, Brigham and Women's Hospital, 181 Longwood Ave., Boston, MA, 02115 USA

Received December 28, 2005; in final form, January 12, 2006

Abstract: The applicability of terminated oligomerization to the synthesis of oligo-(β1-6)-glucosamines, fragments of the intercellular polysaccharide adhesin of staphylococci, was studied. The reactions of terminated oligomerization were carried out with mono-, di-, and trisaccharide monomers and N-protected aminopropanol; and spacered mono- and disaccharides as terminating molecules were also attempted. The primary formation of cyclic products of monomer intramolecular glycosylation was observed in almost all the reactions. Only the experiments with the monomer based on the disaccharide bromide under the conditions of the Helferich reaction led to reduced yields (30%) of the cyclic products. However, even in this case, the desired terminated oligosaccharides were generated in approximately 10% yield and mainly were the products of single glycosylation of the terminator by the monomer. These experiments allow the conclusion that, under the examined conditions, the reaction of terminated oligomerization could not result in the synthesis of oligoglucosamines with a high molecular mass.

Key words: cyclic oligosaccharides, oligo-(β1-6)-glucosamines, terminated oligomerization

Russian Journal of Bioorganic Chemistry 2006, 32 (4):389-399