The interaction between GalCer and gp120 is important for HIV infectivity in CD4 negative as well as CD4 negative cells. Molecules that hinder the interaction between gp120 and GalCer are of interest as potential entry inhibitors of HIV. Novel galactose 1-β→1-α mannose O-disaccharide GalCer analogs, with one or two fatty acid esters on various positions on the mannose residue were designed as mimetics of GalCer, in which the mannose residue serves as a rigid ceramide substitute. The synthesis of these analogs and their interaction with gp120 in a monolayer-binding assay will be presented.