Synthesis of building blocks of human milk oligosaccharides. Fucosylated derivatives of the lacto- and neolacto-series.

The synthesis of protected fucosylated derivatives of a Galbeta(1-->3)GlcNAc and of lactosamine Galbeta(1-->4)GlcNAc building blocks contained in human milk oligosaccharides is described. Both chemical and enzymatic methods have been exploited for selective protection of the disaccharide. Fucosylation of the appropriate derivatives allowed an easy and relatively short access to different products from common precursors.