To gain a better understanding of the conjugation chemistry taking place at the interface of the capsular polysaccharide repeating units, described herein is the synthesis of two disaccharides. These disaccharides correspond to the connection point of the repeating units of capsular polysaccharide S. aureus serotype 5 (CP5) and serotype 8 (CP8). As in our previous syntheses of trisaccharide repeating units, the potential propagation positions are blocked with methyl groups.