Selective cross-metathesis of C-allyl-glycosides

The efficient and selective cross-metathesis (CM) of both the alpha- and beta-anomers of C-allyl-glucose and N-acetyl-C-allyl-glucosamine with electron-deficient olefins is reported. The applicability of our CM approach in the synthesis of glycoside-conjugates is illustrated by the CM of alpha-C-allyl-glycosamine 2 with uridinyl vinylphosphonate 22, to produce UDP-GIcNAc analog 23.