Total Synthesis of alpha-Linked Rha-Rha-Gal Undecaprenyl Diphosphate Found in Geobacillus stearothermophilus

Abstract

A (2+1) glycosylation approach was employed to construct the core structure of a trisaccharide found in the soil bacterium Geobacillus stearothermophilus. The phospholipid was assembled by the reaction of a peracetylated trisaccharide bearing an anomeric hydroxy group with phosphoramidite and subsequent oxidation to the phosphate. The final coupling step with undecaprenyl monophosphate followed by global acetate deprotection completed the total synthesis of the highly amphiphilic target molecule.