Difunctionalization of Glycals and their Derivatives: Strategies and Applications in the Synthesis of Bioactive Compounds

Glycals serve as crucial donor molecules in the synthesis of biologically active compounds. These moieties can undergo functionalization at various positions, such as C‐1, C‐2, and di‐functionalization at multiple sites, including 1,2‐difunctionalization, 2,3‐difunctionalization, and 1,3‐difunctionalization. Among these, 1,2‐difunctionalization can be achieved using diverse methodologies, including metal‐catalyzed reactions, cyclopropane ring opening, epoxide ring opening, and more. Additionally, glycals can be converted into dihalogenated compounds through simple and efficient protocols.Moreover, the 1,3‐difunctionalization process typically involves glycosylation at the anomeric position, followed by the attack of a suitable acceptor. These transformations have proven instrumental in synthesizing various medicinally significant molecules, such as restricticin, SGLT‐2 inhibitors, bergenin, papulacandins A‐D, and tricyclic flavonoids. This review provides an overview of the diverse strategies employed for the difunctionalization of glycals and highlights their application in synthesizing difunctionalized natural products.