Forssman pentasaccharide

In early work [165] on the synthesis of the pentasaccharide (236), the azide (237) was condensed with (238) [an intermediate in the preparation of (237)]in the presence of silver perchlorate and polyvinylpyridine to give the a-linked disaccharide (239) in 60 % yield and this on acetolysis gave the disaccharide (240) which contains the potential terminal disaccharide unit of the Forssman antigen. Compound (240) was converted into the glycosyl bromide with titanium(IV) bromide under carefully controlled conditions [182] and condensed with l,6-anhydro-2,4-di-0-benzyl-D-galacto-pyranose in the presence of silver carbonate to give the potential terminal trisaccharide (241) of the Forssman antigen. 

The synthetic pentasaccharide showed similar antigenic specificity to the Forssman glycolipid but because of the absence of the lipid portion did not form a stable complex with the Forssman antibody [187],... 

Acetamido-2-deoxy-a-D-galactopyrano-syl)-(I - 3)-(2-acetamido-2-deoxy-fi-D-galactopyranosyl)-(I - 3)-a-D-galacto-pyranosyl-(I ->4)-p-D-galactopyranosyl-(1 - 4)-D-glucose. Forssman specific pentasaccharide [71937-76-3]... 

Two reports have appeared on the preparation of the pentasaccharide (78) of the Forssman antigen. 

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