An efficient method for the synthesis of a 1,6-anhydro-alpha-D-galactofuranose derivative and its application in the synthesis of oligosaccharides

Synthesis of 1,6-anhydro-2,3,5-tri-O-benzoyl-beta-D-galactofuranose (3) has been achieved in good yield by stannic chloride catalysed ring closure of methyl 2,3,4-tri-O-benzoyl-6-O-benzyl-beta-D-galactofuranoside (1). The anh ydro compound 3 was converted to the furanoside donors 6 and 7 with an easi ly removable O-6 acetyl group. The donors 6 and 7 were utilised for the syn thesis of a di- and a trisaccharide containing beta-D-galactofuranosides.