Selective Anomeric Deacetylation of Per-Acetylated Carbohydrates Using (i-Pr)3Sn(OEt) and Synthesis of New Derivatives

Hadi Jabbari

doi:10.5539/jmbr.v10n1p166

Abstract

In this study natural carbohydrates such as glucose, galactose, xylose, fructose andlactose, are acetylated by acetic anhydride and sodium acetate catalyst. Anomeric configuration is deacetylated by (i-Pr)3Sn(OEt)as a catalyst, an easy synthetic regioselective deacetylation of full acetylated carbohydrates using (i--Pr)3Sn(OEt) is described. The acetylated carbohydrates reacted with HBr (solution in AcOH, 32 wt.%) for the bromination of anomeric position. The synthesis oxazaphosphorine, and bromo hexa alkyl Methylsulfonate derivatives from anomeric position of carbohydrates was reacted. FT IR, 1H, 13C NMR, 31PNMR spectroscopy techniques were employed to examine the synthesized compounds.

Highlights

Carbohydrates are a large class of organic compounds which can be found in the structure of living organisms
This paper aimed to describe the full acetylation of some carbohydrates such as D-glucose (1a), D-galactose (1b), D-xylose (1c), D-fructose (1d) and D-lactose (1e) in the presence of Ac2O/AcONa as well as selective deacetylation of anomeric position using3Sn(OEt) as a new catalyst (Scheme 1, Tables 1 and 2).Anomeric configuration is deacetylated by3Sn(OEt)as a catalyst, A convenient synthetic approach to regioselectivedeacetylation of full acetylated carbohydrates using3Sn(OEt)is described
The acetylated carbohydrates are reacted with HBr for the bromination of anomeric position

Summary

Introduction

Carbohydrates are a large class of organic compounds which can be found in the structure of living organisms. They are major energy source for both plants, and animals that play an important role in feeding the living organisms. Likewise, these compounds are quintessential reactions of ATP, RNA and DNA. The existence of an electron-withdrawing substituent (as halogens) onto C1 in axial position is more stable due to the anomeric effect This tendency is not limited to carbohydrates and observes in annular systems like substitutability of 2-tetrahydropyrans. Acetylated-1-hydroxy of carbohydrates contains valuable structures for diverse reactions of glycosides

Objectives

Methods

Results

Conclusion