Ramberg-Bäcklund Approaches to the Synthesis of C-Linked Disaccharides

Readily available S-glycoside dioxides were utilized in a Ramberg-Bäcklund rearrangement for the construction of C-linked disaccharides. This approach is ideally suited to analogue synthesis simply by variation of the alkylating agent, and is illustrated here by the synthesis of beta,beta-C-trehalose (see reaction scheme), a higher homologue of C-trehalose, and methyl C-gentiobioside. Bn=benzyl.