A ring expansion-glycosylation strategy toward the synthesis of septano-oligosaccharides.

A one-pot ring-expansion-glycosylation reaction was performed using 1,2-cyclopropanated sugars as glycosyl donors and carbohydrate O-nucleophiles as acceptors to provide septanohexose mimics of pyranose and furanose derivatives. The methodology was successfully extended to the synthesis of septano-oligosaccharides by adopting a divergent strategy as well as an iterative protocol.