Synthetic studies on glycosphingolipids from protostomia phyla:: Synthesis of neogala-series glycolipid analogues containing a mannose residue from the earthworm Pheretima hilgendorfi

Two kinds of glycosphingolipid analogues from the earthworm Pheretima hilgendorfi were synthesized as follows: the trisaccharide 2-(tetradecyl)hexadecyl alpha-D-mannopyranosyl-(1-->4)-beta-D-galactopyranosyl-(1-->6)-beta-D-galactopyranoside (13) and the tetrasaccharide 2-(tetradecyl) hexadecyl alpha-D-galactopyranosyl-(1-->6)-[alpha-D-mannopyranosyl-(1-->4)]-beta-D-galactopyranosyl-(1-->6)-beta-D-galactopyranoside (20) were synthesized by stepwise condensation of suitably protected monosaccharide units, A 2-(trimethylsilyl)ethyl 2,3,4-tri-O-benzoyl-beta-D-galactopyranoside derivative (5) was used as the glycosyl acceptor and thiophenyl derivatives of D-galactose and D-mannose were used as donors respectively.