Intramolecular glycosylation.

Xiao G Jia,Alexei V Demchenko

doi:10.3762/bjoc.13.201

Abstract

Carbohydrate oligomers remain challenging targets for chemists due to the requirement for elaborate protecting and leaving group manipulations, functionalization, tedious purification, and sophisticated characterization. Achieving high stereocontrol in glycosylation reactions is arguably the major hurdle that chemists experience. This review article overviews methods for intramolecular glycosylation reactions wherein the facial stereoselectivity is achieved by tethering of the glycosyl donor and acceptor counterparts.

Highlights

With recent advances in glycomics [1,2], we know that half of the proteins in the human body are glycosylated [3], and cells display a multitude of glycostructures [4]
Despite extensive studies that have emerged since the very first experiments performed by Arthur Michael and Emil Fischer in the late 1800’s, the glycosylation reaction remains challenging to chemists
To apply the remote glycosidation methodology to the synthesis of the 4,6-branched trisaccharide, phthaloylated thioglycoside 17 was coupled with the 6-hydroxy group of the acceptor precursor 16 in the presence of DCC and DMAP (Scheme 5)

Summary

Introduction

With recent advances in glycomics [1,2], we know that half of the proteins in the human body are glycosylated [3], and cells display a multitude of glycostructures [4]. Presented is an overview of methods that have been developed to achieve higher efficiency and/or better stereoselection by tethering the donor and acceptor counterparts, reactions that are commonly referred to as intramolecular glycosylations. These attachment strategies clearly distinguish the molecular clamp method from other intramolecular concepts wherein the attachment involves one of the reactive sites, acceptor hydroxy group in IAD or the leaving group of the donor.

Results

Conclusion