Total Synthesis of the Lipid-Anchor-Attached Core Trisaccharides of Lipoteichoic Acids of Streptococcus pneumoniae and Streptococcus oralis Uo5

Herein we report an efficient total synthesis of lipid-anchor-appended core trisaccharides of lipoteichoic acids of Streptococcus pneumoniae and Streptococcus oralis Uo5. The key features include the expedient synthesis of the rare sugar 2,4,6-trideoxy-2-acetamido-4-amino-D-Galp building block via one-pot sequential S(N)2 reactions and the alpha-selective coupling of D-thioglucoside with the diacyl glycerol acceptor to construct a common disaccharide acceptor, which was utilized in the total synthesis of target molecules 1 and 2.