Selectivity of 1-O-Propargyl-d-Mannose Preparations.

Ilona Krabicová,Bohumil Dolenský,Michal Řezanka

doi:10.3390/molecules27051483

Abstract

Thanks to their ability to bind to specific biological receptors, mannosylated structures are examined in biomedical applications. One of the most common ways of linking a functional moiety to a structure is to use an azide-alkyne click reaction. Therefore, it is necessary to prepare and isolate a propargylated mannose derivative of high purity to maintain its bioactivity. Three known preparations of propargyl-α-mannopyranoside were revisited, and products were analysed by NMR spectroscopy. The preparations were shown to yield by-products that have not been described in the literature yet. Our experiments showed that one-step procedures could not provide pure propargyl-α-mannopyranoside, while a three-step procedure yielded the desired compound of high purity.

Highlights

Mannose is a natural monosaccharide, occurring in plants as well as microorganisms, usually as a constituent of mannan, hemicellulose, or cellulose [1]
Our experiments showed that one-step procedures could not provide pure propargyl-α-mannopyranoside, while a three-step procedure yielded the desired compound of high purity
The isomers were not reported by Richards et al [22], who used the product for further synthesis without any purification

Summary

Introduction

Mannose is a natural monosaccharide, occurring in plants as well as microorganisms, usually as a constituent of mannan, hemicellulose, or cellulose [1]. Three known preparations of propargyl-α-mannopyranoside were revisited, and products were analysed by NMR spectroscopy. The preparations were shown to yield by-products that have not been described in the literature yet. In addition to the strategies examined in this article, the O-propargylation of mannose can be performed, e.g., via trichloroacetimidate intermediate product [26,27,28,29], or a thioderivative intermediate [30,31].

Results

Conclusion