G. Lemanski et al., Prearranged glycosides, part 10. Intramolecular glycosylation with cellobiosyl, lactosyl, and maltosyl donors, J CARB CHEM, 19(6), 2000, pp. 727-745
Acetyl protected 1,2-O-(1-methoxyethylidene)-disaccharides 1 of maltose, ce
llobiose, and Lactose, respectively were converted via the corresponding be
nzyl protected couterparts 2, the benzyl protected phenyl 2-O-acetyl-3 and
2-O-unprotected 1-thio-glycoside disaccharides 4 into 2-O-succinoylated dis
accharides 5. The latter were esterified with benzyl 2-O-benzoyl-4,6-di-O-b
enzylidene-alpha-D-glucopyranoside (6) to afford succinyl linked derivative
s 7 the benzylidene groups of which were regioselectively opened to give pr
earranged glycoside trisaccharides 8. Intramolecular glycosylation of the l
atter with N-iodosuccinimide resulted in exclusive formation of the corresp
onding alpha-(1-->)-linked trisaccharides 9. No influence of the donor moie
ty on the diastereoselectivity of the intramolecular glycosylation was obse
rved.