Synthesis of two heptasaccharide analogues of the lentinan repeating unit Original Research Article

β-d-Glcp-(1→3)-β-d-Glcp-(1→3)-β-d-Glcp-(1→3)-β-d-Glcp-(1→3)-[β-d-Glcp-(1→3)-β-d-Glcp-(1→6)]-β-d-Glcp (18) and the allyl glycoside of β-d-Glcp-(1→3)-[β-d-Glcp-(1→6)]-β-d-Glcp-(1→3)-β-d-Glcp-(1→3)-β-d-Glcp-(1→3)[-β-d-Glcp-(1→6)]-α-d-Glcp (29) were synthesized as the analogues of the lentinan repeating heptaose by building the pentasaccharide backbones first, followed by attaching the side chains. 4,6-O-Benzylidenated mono-13 or disaccharide 8 were used as the acceptor to ensure the β linkage in the synthesis of 18, while 4,6-O-benzylidenated disaccharides 21 and 23 were used as the donor and acceptor, respectively, to ensure the β linkage in the synthesis of 29.