An Improved Protocol for the Stereoselective Synthesis of β-d-Glycosyl Fluorides from 2-O-Acyl Thioglycosides

A safe and operationally simple protocol for the preparation of β-d-glycosyl fluorides is presented. We demonstrate that a precise combination of XtalFluor-M, N-bromosuccinimide, and Et₃N·3HF can mediate facile, high-yielding, and diastereoselective conversions of 2-O-acyl thioglycosides to β-d- and other 1,2-trans glycosyl fluorides. The key roles of these reagents are dissected in this work, as is the impact of their interplay on the fluorination stereoselectivity.

From Cancer to COVID-19: A Perspective on Targeting Heparan Sulfate-Protein Interactions

Heparan sulfate (HS) is a complex, polyanionic polysaccharide ubiquitously expressed on cell surfaces and in the extracellular matrix. HS interacts with numerous proteins to mediate a vast array of biological and pathological processes. Inhibition of HS‐protein interactions is thus an attractive approach for new therapeutic development for cancer and infectious diseases, including COVID‐19; however, synthesis of well‐defined native HS oligosaccharides remains challenging. This has aroused significant interest in the development of HS mimetics which are more synthetically tractable and have fewer side effects, such as undesired anticoagulant activity. This account provides a perspective on the design and synthesis of different classes of HS mimetics with useful properties, and the development of various assays and molecular modelling tools to progress our understanding of their interactions with HS‐binding proteins.

An efficient and scalable synthesis of 2,4-di-N-acetyl-l-altrose (l-2,4-Alt-diNAc)

An efficient and scalable synthesis of pseudaminic acid precursor l-2,4-Alt-diNAc was developed from l-fucose. The desired l-altro configuration and N-acetamido substitutions ensued from a sequence of highly regio- and stereoselective transformations.