Convenient syntheses of isomaltose derivatives from amygdalin

The isomaltose trichloroacetimidate 7 was synthesized in five steps from d-amygdalin. The key step in this series of reactions was the acid catalyzed rearrangement of the inter-glycosydic bond to give the thermodynamically more stable α-anomer. The reaction was also applied to different di-, tri-, and tetrasaccharide derivatives of amygdalin giving the corresponding rearrangement products.