Preparation of Sugar Derivatives Employed in Glycoside Synthesis

Preparation of Sugar Derivatives Employed in Glycoside Synthesis 

In the first reported synthesis of a glycoside, phenyl jS-D-glucopyranoside,  

Most of the stable 0-acetylglycosyl halides have the a-configuration, 

0-Benzoylglycosyl bromides, made by the action of hydrogen bromide on fully benzoylated sugars, have been employed for the synthesis of methyl and ethyl glycosides, not necessarily with Walden inversion (see Section III, 1). 

Acetic anhydride is used exclusively in making the poly-0-acetylated sugars, and a catalyst is essential. The choice of catalyst determines the predominant anomer obtained. Once isolated, the anomers can be inter-converted by the use of suitable catalysts. The following Subsections deal with the principal catalysts employed in acetylation. 

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II. Preparation of Sugar Derivatives Employed in Glycoside Synthesis. 158... 

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