Synthesis of imino-C-disaccharide related to sucrose

Stabilised ylides 1 and 10, prepared from perbenzylated and peracetylated allyl C-glucopyranosides, respectively, were reacted with differently protected D-serinal; osmylation of the obtained α,β-unsaturated ketones 3 and 12, followed by intramolecular reductive amination, afforded different imino-C-disaccharides 14, 15, 18, and 19 related to sucrose.