Chemical diversification of sialic acid glycosides by stereospecific, chemoselective deamination.

Late bloomer: Nitrosation of peracetylated sialic acid glycosides followed by treatment with sodium trifluoroethoxide and then a suitable nucleophile enables the late-stage modification of these glycosides with stereospecific replacement of the acetamido group. This method should enable access to many glycoside derivatives with a minimum of synthetic effort.