Mannobiosides are dimers of mannose that bind more strongly to lectins than single mannose units. They are useful for studying immune recognition, bacterial adhesion, and lectin–carbohydrate interactions. To improve stability, the glycosidic oxygen can be replaced with sulfur to form thiomannobiosides. These modified molecules remain biologically active while being more resistant to enzymatic breakdown. The thesis focuses on synthesizing a 1,4-thio-linked mannobioside using controlled chemical methods. However, the synthesis is difficult, and the final target compound was not successfully obtained.