INTRAMOLECULAR GLYCOSYLATION OF PREARRANGED GLYCOSIDES - A NOVEL TOOL FOR CONTROLLING THE REACTIVITY AND ANOMERIC SELECTIVITY OF GLYCOSYLATIONS

摘要

The intramolecular (1-->4) glycosylation of partially protected alkyl gluco- and galactosides with ethyl 1-thio-rhamnoside that is preconnected via position 2 with a succinyl spacer to positions 3 and 6, respectively of the glycosyl acceptor affords the corresponding alpha- and beta-linked disaccharides. The anomeric selectivity depends on the stereochemistry of the donor-acceptor-interaction and is influenced by the position of the succinyl bridge. [References: 27]