Programmed chemo-enzymatic synthesis of the oligosaccharide component of a carbohydrate-based antibacterial vaccine candidateElectronic supplementary information (ESI) available: Experimental data for enzymatic glucosylation and chemical synthesis, analytical data including 1D and 2D NMR spectra for all new compounds. See DOI: 10.1039/c4cc08805k

The powerful chemo-enzymatic synthesis of the pentadecasaccharide hapten involved in the first synthetic carbohydrate-based vaccine candidate against endemic shigellosis is reported. The high yielding site-selective α- d -glucosylation of a lightly protected disaccharide by an engineered transglucosylase-sucrose system gave a trisaccharide, which was chemically elongated by an efficient [5+5] process. The powerful chemo-enzymatic synthesis of the pentadecasaccharide hapten involved in the first synthetic carbohydrate-based vaccine candidate against endemic shigellosis is reported.