GLYCOSYLIMIDATES .50. GLYCOSYLATION WITH HIGHLY REACTIVE GLYCOSYL DONORS - EFFICIENCY OF THE INVERSE PROCEDURE

Alpha-Fucosylation with the reactive trichloroacetimidate 1 as donor and disaccharides 2 and 4 as acceptors led to a remarkable increase in yield under ''inverse conditions'', i.e. addition of the donor to an acceptor/catalyst solution. Thus, acceptor/catalyst complex formation enforcing the generation of the glycosylating species in the vicinity of the acceptor is favored yielding building blocks for antigen determinant synthesis