A Ramberg−Bäcklund Approach to the Synthesis of C-Glycosides, C-Linked Disaccharides, and C-Glycosyl Amino Acids

Synthetic applications of exo-glycals, derived from S-glycoside dioxides using the Meyers variant of the Ramberg−Backlund rearrangement, are described. These include a formal synthesis of a β-glycosidase inhibitor 12 and an efficient route to spirocyclic glucose derivatives 17 and 18. The synthesis of C-linked disaccharides 24, 31, and 38 and the C-glycosyl amino acid 49 using the Ramberg−Backlund rearrangement is also reported. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)